Additional keys on Sun Type6 USB keyboard

[professa]

Hi,

I recently snatched a Sun Type6 USB keyboard where it otherwise would have been thrown away and since then I'm desperately trying to use the additional keys of that bitch (like the STOP, UNDO, COPY keys and so on).

I know I can use xbindkeys to bind these keys to actions (using xev, I get the keycodes of these keys and already corrected them in /usr/lib/X11/xkb/keycodes/sun).
But I don't want to start e.g. an xterm when pressing that key but I want for example the UNDO key to emit the sequence CTRL-Z to the currently active window/program.

Is this in any way possible? I have to admit that I don't comprehend the syntax of xmodmap, so I don't know really if this might work...

Thanks in advance, Michael

BTW: using X.Org 6.8.2-r4, kernel 2.6.13-r5, XFCE 4.2.2.