Is it possible to do this: I have a Sanyo Z2000 projector and an onkyo receiver for audio, now what I want to do is control the audio via the onkyo and the directv remote which I know I can do but I want to be able to do it without having to slide the thing at the top of the remote to another source, I want to leave it on the directv source just as if it was a regular TV and it contolling the volume. Is this possible and if so how?