Help With Activator?

So I'm trying to build an adventure level that involves attaching different tools to a vehicle. I want to be able to activate the RC's associated with each tool and be able to switch back to the "Main RC" but I can't quite figure out how to do it when multi-emitters are involved. Is this even possible?

Basically I want one button to actuate whichever RC activator is relevant, allowing the user to swap between the main controls and the tool-specific controls. It only works the first time (un-emitted); if emitted it will fail.

The only "Tool" that has activators on it is the left-most one ("F" on the RC) so don't really bother too much with the others.