I reinstalled XP over an existing installation using a different username (by mistake).
I managed to transfer the "documents and settings/username" folder's content from the previous user to the new one using this process :

How to copy data from a corrupted user profile to a new profile in Windows XP

Outlook express started as it usually does in a fresh windows install with no emails or profile.
I know how to import adrress books and change the email storage folder.

How can I get it to use the previous identity so that I can get the address book folder hierarchy back?

I'm doing this for a friend who spent a massive amount of time arranging the address book into folders.
I tried before to import addresses from a wab file but it just shoved all the addresses into one folder.
I want it exactly as it was before the reinstall.