Try these:
bd/dvd 35278
game 62409
sat/catv 15560
video 1 08393
video 2 65993
tv 45257
sacd/cd 08137
tuner 07881
Your Comcast remote can't do the USB input code unless you buy a JP1 cable ($8 on ebay).
My codes came from here (need join the forum to download and need to install Remote Master software to view the file). All will work on your Comcast except the ones that use Sony20 protocol.
[Link: hifi-remote.com]