Currently, it is not possible to migrate or copy a list of users and their concominant rights/assignments from an existing VSS database to another one, using either shipped VSS features or programmatically, using IVSS.  However, our capable friends in Microsoft's Product Support Services (PSS) have developed a tool that can perform this task automatically. You can download this tool from

If you are the designated VSS database administrator on your team, VSSEMS can help you do much more than copy a user list from one database to another. Check it out. This utility is officially unsupported by Microsoft (or me for that matter :-). However, if you experience any difficulties while using it, please feel free to let me know.