On top of your corporate version, it should retain your settings and registary but then you will have to will have to obtain the numerous activation cracks (or fiddle with the registry manually)
Next you will have to find out whenther your new copy of XP was a retail or an oem and find that article about changing the code (setup.ini) from retail -> OEM -> Corporate. - i.e. If the disc is a retail version it will not accept an OEM key or update key. It is possible to tweak this though. But my memory fails where the article was!
P.S. I haven't tried this yet so don't put any faith in me!
Probably the same for Office XP, I fully uninstalled it the other day and then re-instlalled it and it retained all my settings etc. So no problem there.
I take it this is the beginning of the pre SP1 freeze scare!