Is it possible to import/export radio station as a list into/from Banshee

I have a list of radio stations that I am interested in importing to Banshee. After I add more stations before next upgrade I would like to keep that list somewhere, so it can be imported into Banshee after system upgrade. Is there a way to do it easily? Any hints to where and how Banshee handles this list internally would be appreciated. Thanks!

I think this is not a quite useful answer for you, I'll rather show you or some nice person with time and ambition a way to go.

Because I didn't find an existing possibilty to get what you want (and I think there really is none), I believe the easiest way would be to write a tiny tiny extension. And this really doesn't seem very hard because the code exists already in other extensions.
For example Radio Station Fetcher: it just searches for radio stations on some websites and adds them to your radio "playlist". Therefore it uses a single dialog with two buttons (one for genre search and one for free text search) and that's all (you can try it yourself by installing banshee-extension-radiostationfetcher; you can find it then in the "Tools" menu).
I looked at the code and all one have to do is replace the code for searching stations on those website with code that reads your list of stations. All the other code can almost stay the same. I would do it, but I don't have time.
You can find the code of all extensions here. Live Radio has the same functionality of adding a list of stations to your radio "playlist" but I think it has a bigger codebase to look through.

I hope that will help you or some kind person who will do the work for you :P