Fellow Swede and deployment specialist Mats Olsson was nice enough to contribute with a sample user exit script that is using a text file as the MDT database. This is useful when doing offline deployments, or any scenario where you don't have access to a SQL or SQL Express database.
You simply store the text file (database) in the deployment share, store the script in the scripts folder, and call the user script as any other user exit script. Se sample below:
Download the user exit script and sample database text file
Note: Of course you could add all the text file database info directly into CustomSettings.ini, but like when you are using a real SQL database, it's very nice to have lists of data outside the CustomSettings.ini