Enter customer number to get to destination

Is there away to prompt an inbound caller for a customer number or password before letting them access a destination like a queue or ring group.

The scenario is for screening inbound tech support calls. We have paid users who have a customer number and “demo” users who do not. Only the paid users are allowed “after hours” support. Demo customers go to voice mail.

I have a list of 400 6 digit numbers that I can validate with from a text file or mysql table but if that’s too complicated, counting the number of digits input and checking for 6 would work.