FVWM: emulating mouse button 2 on HP touchpad

I am since ages a keen fvwm user (2.6.8 bundled with ubuntu), mostly on a 
desktop PC, with a personal configuration described in 
http://sax.iasf-milano.inaf.it/~lucio/WWW/Opinions/window.html.

In particular (independently of fvwm ?) I am used to do quick 
copy-and-paste of text selecting it with mouse button 1 (MB1) and pasting 
with mouse button 2 (MB2). Or shift-MB1 and shift-MB2 in my favourite 
editor (The Hessling Editor), due to a peculiarity of the editor.

Now I've got a new HP Probook laptop which has a touchpad without buttons. 
Apparently tapping near the bottom left and bottom right corners of the 
touchpad works as MB1 and MB3 ... but there is no MB2.

I wonder whether there is a solution (either fvwm-specific or X11-generic) 
to achieve a decent emulation of the paste function.

I found a sequence like this

xkbset m ; xkbset exp 5 -m ; xmodmap -e "keycode 105 = Pointer_Button2"

can temporarily assign the MB2-click (for paste) to my right-control key 
(I never use such key). The reason it has to be temporary is that xkbset 
m., enabling the mousekeys, disables the numeric keypad (but I make a lot 
of use of the numeric keypad - with Num Lock off - for specific functions 
in my editor configuration ... actually I quite insisted on having an 
"English International" keyboard to have the num keypad)

I also found mention of a command like "xdotool click 2". Would it make 
sense to assign it with PointerKey in .fvwmrc ?

Or are there simpler or better solutions "
Thanks


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