Assigning remote KEYs to XBMC functions

[degauss5]

Hello:

When I use my MICROSOFT MCE USB remote with the "irw" terminal command all the keys are recognized,

irw
http://pastebin.com/3Yw5zuzE

but in XBMC there are some keys that are not working:
- NUMERIC KEYS (in search boxes)
- LETTER KEYS (in search boxes)

Also, there is no key for the ContextMenu.

I suppose that there is one file with the the assignation of the XBMC actions with the remote keys.. Could be "remote.xml" or "keyboard.xml" in
/usr/local/share/xbmc/system/keymaps ????

Knowing the name of a recognized key, i.e. "KEY_EPG", how can I assign that key to the show ContextMenu action???

Thanks