If you're using HIP/HIPsend, via the '.exe channel changer', then I'm fairly sure there is a command line parameter for hipsend.exe that can be used to tell it to send an 'enter'.
Just for the record, I took your advise and relook at Hipsend command line parameter then I realize I can send anything with Hipsend. So I 've fixed the problem this way:
1. In GBPVR Hipsend command line set-up, instead of {channel}, I put {channel}E, where "E" is the ENTER IRcode in step 2.
2. In HIP set-up, I taught HIP to send ENTER IRcode when received "E"
So now when GBPVR sends {channel}, it will send {channel}E (e.g. 212E, 311E) instead, and, HIP in turn will send the {channel} IRcodes + ENTER IRcode
Thank You! I hope this will help other RCA STB owners. My way of return favor to a great FORUM!