I want to create a dynamic where a radio station can offer to their users a URL that will connect them to a page within countryshowdown.com. Ideally, I want that URL to be countryshowdown.com/WKKY. In other words, I want to know how I can set things up on my server so WKKY can plug that URL in and be redirected to a countryshowdown.com/radio_station.php?id=14. Can I do this without having to create 420 individual folders, each named after a station's call letters.
When I go out to youtube, for example, the URL is youtube.com/brucegust. I doubt they have a directory on their server entitled, "brucegust," but how are they doing it and how can I create the same kind of dynamic?