Yes, if you have an QlikView Server Enterprise Edition license
On your server, create an ODBC connection to your Excel file containing user definitions. Then add a DSC of type "Configurable ODBC" and let it read user IDs through the ODBC connection you created in the previous step.
Don't forget to switch your web server away from the default login page to "Alternate login page" (or "Custom login page" if you're feeling lucky) and switch your QVS to DMS mode.
