The first thing you should do is look at your current path were your DBX files are stored, then go there in Windows Explorer and take a copy of the folder as a backup. That way if you mess anything up, you can always open your old email structure from the backup.
You have a number of different options in terms of reading recovered DBX files:
1. You can create separate folders for the DBX files you have recovered and change the Store folder to point to them (run Outlook Express, TOOLS/OPTIONS/MAINTENANCE/STORE FOLDER).
2. You can experiment with creating different Outlook Express "Identities" (run Outlook Exrpess, FILE/IDENTITIES/CREATE NEW IDENTITY). Look at the store folder for the new identity created, and put your recovered DBX files in this store folder. The advantage of this is that you can "switch identities".
3. Try using a tool like Mailbag assistant,
http://www.fookes.com/mailbag/.