[overstrike]If you have the title, content, etc as a variable, then it's easy. Encapsulate that in RSS compatible tags. Otherwise, you're going to have to parse it; regex is your friend for that.
If you're using a DB I could probably whip you up a solution for a few bucks. I recently implemented
RSS 2.0 for
SBL.[/overstrike]
I parsed you backwards. If you want to include RSS in your content, you're going to have to be able to read the feed, parse it, then convert it back to HTML.