Might be a stupid question, and I dont know that you can, but..

I'v got a nice MMO mouse with 12 buttons on the side that I'm making an action list for in reaper. I want to beable to do everything with the mouse. Play, record, split, glue,.... all that shit. I'v got that no problem.

But I'd like to beable to use the 3rd mouse button to work like the control key works.

For example, i have 2 separate takes on the same track and I want to glue them together. I have to reach over to my keyboard and hold the control key to high light the 2nd take. I want to use my 3rd mouse button to take the place of the control key.

Does the control key have a function(I cant find it in the list) and can it be mapped or is it some system level thing I cant fuck with?