Interesting Idea. Not sure who you'd use variables to make that happen.
Seems do able out of a vector, but at some point you would need to "route to digits" and you would have had to have put in the FAC for PSA somewhere along the way. You could just tell everyone their password is the FAC + the 4 digit password. For example, mr customer, if you chose 1234 for your password its actually 222 1234 when prompted.
If you figure it out with variables or some combination of variables, be sure to post the results here. I'm always interested in how ppl have used them in programming, expescially outside the box kind of stuff.
RTMCKEE
CM 2.1.1
Prologix R9.05
Modular Messaging 1.1