Assuming the "InputAux" is the cycling command, then in the "Adjust Inputs" for the dummy device, you would select the 1st option (I flip through the inputs until I get to the right one). List only the 3 Aux inputs in the right order, and select the "InputAux" for the cycling command. It will track the aux input of the dummy device but you will need to synchronized it first. Note: This will work (stay synchronized) only if the Aux input does not get reset by the other direct input command like InputDVD. In this case, you will have to use method #1 (the preferred method). Also don't forget to answer the questions (skipping unused inputs, stay on same input after a power cycle) properly. In the activities that use one of the Aux inputs, select the real device as usual but with a bogus input (as explained by Akirby), and add the dummy device. It will ask you what input to use for the dummy device.