Am I missing something obvious? I can't find RS232 codes/commands to pass the numbers 0-9 to the Denon AVR 3313ci. Someone told me that that could only be done by IR. That makes no sense. The custom installers choice of RS232 can't be used to input numbers to change radio channels for instance! Please tell me this is not right. There have to be RS232 codes/commands for these?

Thanks for any enlightenment.