I know this isn't what your looking for but here's my solution provided you have space for a touchpad. With the touch pad you will be able to control the PC without having to touch your screen. Secondly with the touch pad the upper right had corner (the light grey triangle) acts as a right click.
You can use a free utility autohotkeys to bind right click to emulate any key on the keyboard (i.e what ever key your front end uses to envoke voice command) then simply tap the upper right hand corner of your touchpad to evoke voice commands.
Works great for me
