instead of trying to hack into a usb keyboard you could use an Xbox1 controller with a USB lead soldered onto it
install XBCD for the xbox to pc drivers. http://www.redcl0ud.com/xbcd.html
you can remap the xbox controller buttons & directions with XBCD
or an el'cheapo usb game controller from dealextreme will also work like this http://forum.arcadec...p?topic=84548.0
then use joytokey to remap the XBCD/el'cheapo setup to the keystrokes you need. http://www.electraco...ish Version.htm
once you have it setup to your liking you'll probably want to hide windows and it's boot screen
you can use instantsheller. http://www.gameex.ne...tantsheller.zip
Use at your own risk.
I've just setup a jukebox with the above process,using an xbox1 controller i was able to get 13 buttons to register as keystrokes that i needed.