Great replies, and helpful for others.

The reason I'm looking for discrete MR Source codes is for the Main Room. There are no remote IR receivers, and the customer wouldn't want to go aim at one to control things, It all needs to happen in the Family room. If I install a remote IR receiver in the Family Room and Route it into the back, when I try to tell the MR to go to CD, the Main Room will as well.

The work around is a BLIND toggle ... Send ENT, CRS DWN, CRS DWN, ENT, MR ON, CRS DWN, CRS DWN, CRS RT, CRS DWN, CRS DWN, CRS DWN, CRS RT, ENT(Will toggle MR to ON and NEXT Source). This takes you through 9 sources, so It could take the customer upto 8 presses before they hear their desired source. Clunky, but reliable. I could easily make discrete for all sources if there was a way to always get to one source :-)