I am not sure if this post should be in this forum, if not please forgive me.

I am thinking about building a pvr if I can resolve this issue.

I am on a analog cable system, some of my channels are decoded by my cable box... From what I understand this is no major issue, all I would need to do is purchase a IR blaster and have it change my cable box to the right channel....

Well my problem is, my cable box does not have a universal code for the remote; ie: I must use the remote that came with it and it does not work with any "universal remotes".

Is there a "trainable" type setup available that would allow me to program the IR blaster by purchasing a IR reciever,l and using my cable box's remote to program the pc, so that the pc could emulate the IR signals from my remote?

lirc/winlirc both have a facility for capturing raw codes
raw codes can then be transmitted as is, or "optimized" (makes for a smaller config file)..and then transmitted.

in any event, its possible.. i've done it (i used winlirc to capture)