Well, I’m not at all sure about this—one seldom dares to be sure about anything where Alan Partridge is concerned. It may be a joke. If you look at the penultimate paragraph of this article, then you see why I’m hesitant. Not sure if it’s actually about Philippa Langley, but one thing you cannot say about her is that she’s ordinary!
Addendum: This film seems definite. You will learn more here.