It could be done this way, but frankly, Abiword's Word importer isn't very good. OpenOffice's, while not perfect, is much better. Unfortunately, unlike Abiword, OOo doesn't come with a nice command-line utility for doing those conversions. OOo has a VBA-esque language that allows you to automate tasks like that, but it's a lot more suitable for more "interactive" purposes than as part of another app's backend.

Another thing to note is that some of Scribd's backend is written in C#. Maybe if your app is Windows based, there are Office API calls that let you do stuff like this. Just a guess, though.