The list of buttons you can bind:

Alphabet: A - Z
Numbers: 0 - 9
Function keys: F1 - F12
Punctuation: - [ ] / \ ' . , ; ~ =



Arrow keys:       
UPARROW, DOWNARROW, LEFTARROW, RIGHTARROW



Numeric keypad: KP_HOME, KP_SLASH, *, KP_MINUS, KP_UPARROW,
KP_DOWNARROW, KP_LEFTARROW, KP_RIGHTARROW,
KP_PGUP, KP_5, KP_PLUS, KP_ENTER, KP_END,
KP_PGDN, KP_INS, KP_DEL



Left mouse button: MOUSE1
Right mouse button: MOUSE2
Middle mouse button: MOUSE3
More mouse buttons: MOUSE4/MOUSE5 ( some mice have extra buttons )
Mousewheel scroll up: MWHEELUP
Mousewheel scroll down: MWHEELDOWN



SPACE, TAB, SHIFT, CTRL, ALT, ENTER, BACKSPACE PAUSE
INS, HOME, PGUP, DEL, END, PGDN