Doug Adams is the iTunes guru; he's written 466 AppleScripts for manipulating iTunes, including Doug's AppleScripts for iTunes - Managing Playlists, one of which may be what you're looking for.

If you don't see your answer, email him with your question; he's extremely helpful.

The new Great Equalizer is the SEND button.

In Memory of Harv: Those who can make you believe absurdities can make you commit atrocities. ~Voltaire