Need help: I have Directv genie remote RC66RX & trying to program it to operate my Yamaha RXV379 A/V unit in the AV2 slot of my Directv remote.

Several of the codes listed on DTV site: 30176, 31276, & etc... allow me to control volume (up, down, mute) & a few allow me to control volume & turn off the Yamaha A/V unit, but not turn it back on. I have to use the Yamaha remote to turn unit on.
I know this thread is old, but has anyone found the code(s) or setup process that will allow on/off and volume control using the DTV remote. A forthcoming Blue Ray/DVD player will use AV1 slot on DTV remote, so I prefer not to use that slot just for on/off capability.