The Comcast remote (red OK/Select button--is that what you have?) when using the built-in setup code 01877 puts 00249 on both the MyDVR and the OnDemand buttons. The remotes delivered to our house have a Comcast-installed upgrade which puts 00249 on MyDVR, and nothing on OnDemand. I suspect that the SA cable boxes don't respond to OnDemand. Where we live, however, simply entering 001 in Cable mode calls up OnDemand. If that works for you, we'll be able to program a macro onto the OnDemand button to send channel 001.

However, to return the remote to as delivered condition, the following may work, depending on how the remote was setup at Comcast.

1) Press Setup until 2 blinks
2) Enter 977
I expect the remote will blink 4 times.

Finally, if the 977 command doesn't make A, B, and C work,
A is 00117
B is 00058
C is 00054

Edited to fix typo.