Checking user's credentials

Hi

I build an app in Excel where user is obligated to enter a user name and
password. If the given user name with password exists in an Access database
the application will start.
But how to check if the given user (with such password) exists in the mdb
file? I wouldn't like to try to run a random query to see if it returns
results. I was rather thinking about something more advanced - a solution
that checks only the user name and password. In VBA of course.


Kind regards
IgorM