active directory password

windows 2000 advanced server running active directory. I need to expire an ou groups password immediately and have it expire every few months.

I right clicked on the OU and went to group policy. windows setting, security, password policy.

I can see where I set the max. password age, but where to I expire it immediately?

Thanks.

(We are being hit with an email that asked for the firewall admin name and password, and students are typing it there name and password. So I want to make them change there password immeditely.)

 

This should do it for you I think.