Have you ever tried an older pioneer receiver's remote? My old vsx-d1s, it's remote has twelve inputs, with individual buttons. I also have a remote to a vsa-1000, in which it has thirteen inputs. They're labeled VCR1,VCR2,VCR3,VDP,TV,VIDEO1,VIDEO2,TAPE1,TAPE2,LINE,CD,TUNER,PHONO. The code to one of these must have been relabeled AUX. I don't have a pronto, so I can't give you the codes, but there must be some in the files.