I have already set up 2 handed input combinations the old-fashioned way.

Use the software that comes with the mouse and make mouse4 = ctrl and mouse5 = shift. Then just push mouse4 and the button for 5 on the keyboard or n52 and you get ctrl-5 instead which can be remapped or macro-ed as needed.

Plus it's a free function of the setpoint software which came with the mouse and is already installed.