Direct TV TC64R remote does not work in RF ...

I just bought a Direct TV RC64R remote to replace a RCA D770 remote to work with my RCA DRD486RH receiver. I had to program the RC64R to work with the receiver (code 00392).
The IR mode works with the receiver but the RF mode does not. On the old D770 to program the RF mode, if needed, you went to a RF menu screen on the receiver and from this screen held down the DirectTV button on the remote while entering a 3 digit code (000-255) then letting up on the DirectTV button and pressed the select button. This locked the remote to the receiver. I used the default setting so did not have to program the remote(D770). I am trying to replace the D770 because some of the number keys are not working. Since the new RC64R doesn't work in RF mode I was wondering what key combination would work on the remote to program it to the receiver since there is no DirectTV button to hold in. I called DirectTV tech support and they could not help. After being transferred and put on hold I was told the remote would not work in RF mode with my receiver. I am not sure I actually believe that and would like to know if anyone has any input.