So the inbox is corrupted but you want to maintain the other folders that are subfolders of the inbox. Each of the folders has its own dbx file in the same place where your data is stored.
Close Outlook Express – make sure it is closed!
First you can try renaming the inbox.dbx file to oldinbox.old.
Then open Outlook Express did it recreate a blank inbox and still have your other folders present?
If yes you are done it not then try copying out the dbx files of the folders you want then deleting the outlook express account. Creating a new one.
Now copy those dbx file (except INBOX!) to where the new data files are and you should be in business!