Swap touchpad button 2+3; ignore touchpad button 2; make key work as button 2

Question

My touchpad's middle button is sick: It activates at random times (Maybe it was the juice I spilled on it, who knows?).

I use the middle button all the time, but I have simply remapped button3 and disabled button2:

xmodmap -e "pointer = 1 0 2"

That works, except I need button2 now and then.

How can I map button2 to a key? E.g. LWIN.

I have tried:

xkbcomp "$DISPLAY" - |                                                       
            perl -pe '/key <LWIN>/ && s/\[.*\]/ [ Pointer_Button2 ]/' |              
            xkbcomp - "$DISPLAY"

But it simply disables LWIN; my guess is that it sends Pointer_Button2 which I have removed with my xmodmap above.

So can I have my cake and eat it, too? Can I have the touchpad's button2 ignored? And LWIN/MENU/COMP act like button2?