Nad receiver code for comcast remote?

... I have a a NAD receiver and its remote control unit is not fully functioning i.e., I did replaced with new batteries yet it does on control the functions in the receiver. Whatever the keys I just press on the remote, I find the light and that is all, just the light on the keys but no functions at all.

What could be the reason for it? I also notice, a tiny red colour butten just on the middle of the remote and it reads LEARN. Should we need to reset this or what I really should do.

Please help me

Jazeel, ajmjazeel@Yahoo.com