Not sure where my many posts on this have been hiding. Here's an excerpt from my pkl.ini file at any rate (unless particularly interested, don't read the whole wall-of-text at the end!):
; These keys are modified/transposed by holding down the 'extend key' (CapsLock by default):
;+------+------+------+------+------+------+------+------+------+------+------+------+------+
;|Esc + |F1 <> |F2 << |F3 >> |F4 <> |F5 <> |F6 << |F7 >> |F8 <> |F9 <> |F10<> |F11<> |F12<> |
;| Caps | Play | Prev | Next | Stop | Mute | Vol- | Vol+ | Media| BrHom| Mail | App1 | App2 |
;+======+======+======+======+======+======+======+======+======+======+======+======+======+
;|` ¤¤¤ |1 |2 |3 |4 |5 |6 |7 |8 |9 |0 |- |= |
;| Del | F1 | F2 | F3 | F4 | F5 | F6 | F7 | F8 | F9 | F10 | F11 | F12 |
;+------+------+------+------+------+------+------+------+------+------+------+------+------+
;|Tab |Q ¤¤¤ |W *** |F <<> |P <>> |G *** |J ### |L ### |U ### |Y ### |; ¤¤¤ |[ ¤¤¤ |] ¤¤¤ |
;| | Esc | *WhUp| BrBck| BrFwd| *Btn1| PgUp | Home | Up | End | Del | Esc | Ins |
;+------+------+------+------+------+------+------+------+------+------+------+------+------+
;|Caps+ |A +++ |R *** |S +++ |T +++ |D *** |H ### |N ### |E ### |I ### |O ¤¤¤ |' ¤¤¤ |\ ><> |
;| ++++ | Alt | *WhDn| Shift| Ctrl | *Up17| PgDn | Left | Down | Right| Back | Apps | BrFav|
;+------+------+------+------+------+------+------+------+------+------+------+------+------+
;|Z ¤¤¤ |X === |C === |V === |B *** |_ *** |K *** |M *** |, *** |. *** |/ *** |Spc ¤ |Entr¤ |
;| Undo | Cut | Copy | Paste| *Le17| *Dn17| *Ri17| *Btn3| *WhLe| *WhRi| *Btn2| Enter| Break|
;+------+------+------+------+------+------+------+------+------+------+------+-------------+
;Legend: # Movement; + Modifiers; = GUI edit; * Mouse; <> MultiMedia; ¤ Various commands.
; NOTES:
; - This map shows a 'comfort' Colemak with VK_102 in the middle (the '_' key). See below.
; * The actual remaps are by scan codes though, so the positions are layout independent!
; - Multiple extended mappings would've been nice; this setup is a general/basic one.
; * For instance, accelerated nav/mousing, NumPad/maths, mirroring, coder's toolbox...
; - If your layout doesn't define the key, 'extend' won't work with it!
; * Solution: Put, e.g., 'SC039 = SPACE VirtualKey' etc in your layout .ini file.
; * You'll need at least Escape/Space/Return/Back and F1-F12 for full functionality.
; - The Tab key is currently a poor candidate for remapping because of problems with AltTab.
; * It might be useable as another extensor/modifier though? (Probably best left alone.)
; - My WARS = modifier block idea didn't work because R cannot map a modifier! A bug?!
; * R can map non-modifiers, so I settled for another solution for now: The mouse wheel.
; * My preferred way would have browsing/modifiers more ergonomically/logically placed:
;+------+------+------+------+------+------+------+------+------+------+------+------+------+
;|Tab |Q ¤¤¤ |W <<> |F <>> |P *** |G *** |J ### |L ### |U ### |Y ### |; ¤¤¤ |[ ¤¤¤ |] ¤¤¤ |
;| | Esc | BrBck| BrFwd| *WhUp| *Btn1| PgUp | Home | Up | End | Del | Esc | Ins |
;+------+------+------+------+------+------+------+------+------+------+------+------+------+
;|Caps+ |A +++ |R +++ |S +++ |T *** |D *** |H ### |N ### |E ### |I ### |O ¤¤¤ |' ¤¤¤ |\ ><> |
;| ++++ | Alt | Ctrl | Shift| *WhDn| *Up17| PgDn | Left | Down | Right| Back | Apps | BrFav|
;+------+------+------+------+------+------+------+------+------+------+------+------+------+
; - A Win key wouldn't be very useful here since nearly all Win hotkeys use letters/nums.
; * It might be put in because of Win-F1/F3, Win-Break and the Start menu.
; * Tip: T+Q (Ctrl-Esc) shows the Start menu too. Win-Help/Win-Search are on that menu.
; - Tech note: The mappings are on the form Send {Blind}{%YourMapping%} (see the AHK Help).
; * Thus, if you want, say, a modified keypress you can use, e.g., '}#r{' or '}^{Left'.
; - There isn't a sendable Undo key per se, oddly enough. (Ctrl+Z isn't a hard reach though.)
; * However, A+O (Alt-Back) = Undo (http://www.geocities.com/ian_springer/winkey.html).
; * Actually, it'd be nice to be able to Send any APPCOMMAND_ message but AHK doesn't...
; * APPCOMMAND candidates: UNDO/REDO, NEW/OPEN/CLOSE, PRINT...
; - Mapping something to the Sleep key doesn't seem to do a lot on many computers.
; - The Pause and CtrlBreak are usually both on the same physical key, which is a bit weird.
; * Using Pause, Win+Enter is System Properties.
; * Actually, both Pause/Break and SysRq/PrntScrn send their codes strangely.
; * Hence, I didn't remap any of them to avoid trouble.
; - The AppsKey and Btn2 may seem to do the same, but the menu appears in different places.
; - Mapping Del or Back (or something else?) to the ` key was a bit of a toss-up.
; * For instance, use S+` (Shift-Del) to delete a file bypassing the Recycle Bin.
; * The Back key is handy when navigating - but that's 2-handed work anyway.
; TIPS:
; - These mappings enable you to do many things without leaving the typing home position.
; * Mappings are based on ease of reach vs. usefulness, and some left-hand-only use.
; - This could take some getting used to for the left pinky, but it gets really cool!!!
; - The Caps key plus Esc turns the CapsLock state on and off now.
; - It's handy to control your browser back/forward with the left hand only while browsing.
; - Similarly, the wheel up/down keys are favorites.
; - Space for Enter is also nice; can be worked with left-hand-only as well.
; * To press dialogue buttons for instance, use Tab to move and Space/Q to select/abort.
; * A+Space (=Alt+Enter) when a file/disk is selected, brings up the object's Properties.
; - Use the Apps (or *Btn2) for context menus; arrows, 'mousing' or shortcuts select items.
; - Esc mapped to '[' (Telnet/Vim/etc compliant) is okay, but a left-hand one is even better.
; - The left-hand Del key is also convenient; the right-hand one is best when editing.
; - Cut/Copy/Paste are Windows 'multimedia board' versions - should work mostly anywhere.
; - Using S/T (Shift/cTrl) with the UNEI/LY/O' keys you can jump words, jump/select, etc.
; - The number keys are mapped to function keys. They are reachable with the left hand!
; * A4 closes apps; Win+3 GUI-searches; try 1(Help)/2(Rename)/3(Find)/5(Refresh) too.
; - The function keys are mapped to multimedia keys like the ones on multimedia keyboards.
; * Browser_Stop/Refresh/Search are usually covered by hotkeys (e.g., Esc/F5/^F).
; * Browser_Favorites usually needs a menu choice, so that's included (near the arrows).
; - The App1/2 keys are defined in the registry, in ShellExecute (REG_SZ) values:
; * HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\AppKey\17
; * HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\AppKey\18
; * You could also do user-specific ones in HKEY_CURRENT_USER (might have to create them).
; * Usually though, I find that the defaults of Explorer (App1) and Calc (App2) are fine.
; * The Mail one lies in AppKey\15, Media in 16, and Browser in 7. Can change those too.
; - Wheel Up/Dn are nice for scrolling windows/bars; Wheel Left/Right for horizontal scroll.
; * Horizontal scrolling doesn't always work though, at least not before Windows Vista.
; - The 'virtual mousing' is rudimentary; a 'last resort' when arrows/Tab aren't enough.
; * The 'mousing cross' is placed similarly to the 'mouse stick' on some boards.
; * A mousing resolution of 17 pixels roughly fits *most* context and similiar menus.
; * A full mouse layout could have multi-resolution, diagonals, Btn4/Btn5 and sticky Btn1.
; * The keyboard's auto-repeat makes virtual mousing odd/'laggy' when a key is held down.
; * In particular, beware of holding down the *Btn key(s) for a 'rapid-click' effect.
Also, here's a color map (I've been wanting to add icons to that but haven't yet):
Note that I want to use more than one Extend state so I can add a NumPad and other stuff, including accelerated navigation (5 at a time or thereabouts for the arrows, larger mousing jumps). I'm thinking that, e.g., Alt+CapsLock will switch to this state (and then you let go of the Alt key). The mouse functionality isn't all that good but it's sometimes handy.
