Need remote code for Panasonic TV CT-3207D

I cannot successfully program my DirecTV remote to work with my TV any longer. It did work at one time, but not any longer. I tried reprogramming all of the codes listed from my R22 receiver, but I cannot find the one that controls the volume.

Does anyone know which of the many codes will actually work? I have tried them all, but have had no success.

Thanks!