Would your Access application be open at the time? Or do you want to do this through a Scheduled Task, perhaps?
If the db is open, the Jeff's link will give you the right sort of answer.
If the db is NOT open, then you'd have to use a scheduled task and call a Macro in the databse (or something along those lines). Also, if this database is secured with UserLevel Security, then you won't be able to do this (you mentioned a Username and Password, so I'm not sure what that entails).