RSS feed customization

Hello fellow WordPress users.

I don’t have much experience with RSS feeds but what I was thinking of doing on my blog was to have an RSS feed that posts content automatically with a link at the end to a site. So the RSS feed is normal the only add on is the fact that with every post there is a link to another site.

So my question is: Is it possible to have something that automatically adds a link (or piece of html) to every RSS feed post?

I was thinking that a way of doing this could be to assign RSS feeds as if they are coming from a certain author. And put the link in the signature. I don’t know how viable that would be…

Or possible I would have to put something in the RSS code.

Anyone have any thoughts/experience in this area?