Very Computer

I wonder if the following can be done with X.

I'd like to use my left shift/ctrl/alt keys with mouse click to
generate the same events as if I'd pressed the mouse buttons 1/2/3.  I
am not really familiar with xmodmap or such, but I suspect that it
might be done. Could you enlighten me?

My main reason for this awkward request is that I am trying a new
pointer called 'glidepoint' where you move your finger on a small
tablet and it moves the pointer on the screen accordingly. It has
three buttons plus if you tap the tablet it generates a mousebutton 1
click. (doubleclick works too.)

Now the problem is that I find very hard to press a button and move my
other finger at the same time. So I thought of the requested solution
since my left hand is free anyways when using the "mouse".

I prefer direct email, but will read the group for answers too.
Thanks a lot,

        Tamas Badics