Help setting up n64 keyboard control

Hi there, I’ve done heaps of reading and can’t figure out the names of all the key bindings for retroarch.cfg – I’m currently using the libretro-mupen64plus, but could also use the non-libretro if need be?

I’m actually trying to set up an IPAC which shows up as a keyboard via USB, but any general help in keyboard bindings will help.

Thanks