I have this combination working great with WMC and XBMC on Vista using my Harmony 880, USB-UIRT and EventGhost. I didn't need to edit the keymap.xml at all:
I have one "activity" on my Harmony that turns on the PC, sets the volume controls to my reciever and sets each button on the remote to do both an innate XBMC action (through the XBMC plugin in EventGhost) as well an emulated keystroke. I did this for each button except when the keyboard shortcut in WMC also did something in XBMC (up, down, left, right, enter). For example, I have the FFW button on my Harmony execute the "Fast Forward" action in XBMC as well as emulate the keystroke CTRL+SHIFT+F.
I have the computer boot/wake into XBMC through EventGhost. Fortunately USB-UIRT has a built-in wake-from-USB function.
I have a button on my harmony called "Switch to TV" that closes XBMC and opens, activates and maximizes WMC.
I have another button on the harmony, "Switch to XBMC" that closes WMC and opens and activates XBMC. This doesn't close any recordings if you just close eshell.exe.
I bound all of the other Harmony buttons to their respective actions.
When I first did this, I couldn't get the XBMC actions to be repeated correctly through my Harmony/USB-UIRT/EventGhost.
Solution: Emulate the keystrokes for actions that you want to have repeated instead of using the innate XBMC action. This allowed for really responsive repeated actions in XBMC when holding down a button and also lets you use the same "Activity" for both WMC and XBMC, which I think is essential for seamless WMC-XBMC transitions.
WMC keyboard shortcuts:
http://windowshelp.microsoft.com/Windows...61033.mspx
