i am using this solution.
I am using two IR emitters.
I will use an X10 lamp module, 12 volt power supply and a 12 volt relay with spdt 12 Volt coil relay.
I simply switch the throw of the spdt relay to select which hopper would get the IR code. At any point, only one hopper will get the IR code.
In the URC 780, simply add a code to turn on or off the relay accordingly, into the macro of the source selection button. Simple, my dear watson. I am disappointed I didn't think about this sooner!