Help with setting up server...

Basically, I want to use a program called MyTunesRSS which makes my computer act as a server so that I can use the rss feature to play songs from my itunes DB on any other PC with internet access. Now, i have gotten comodo PF set up so that through LAN I can properly connect. However, when i want to access MyTunesRSS from a computer that isn’t on my network, comodo blocks the traffic. I was wondering if it would be possible to allow ALL traffic for this app only through comodo. Any help is greatly appreciated. Thanks.

I assume you mean, not on your network = on WAN. Do you have a router with FW enabled?
In general, for Comodo to allow incoming, you must make a rule for Incoming in Network Monitor, as tight as you can for security. Lets say you want anyone to access that. You need to know what port is used by that program, and make a rule for INcoming, on that port, on the TCP protocol.

A good link (assuming this is the program you mention):