Win2k Rights Assignment

Dear All,
I am Win2k Administrator in a network of about 150 nodes.

My question is about the permission to lock/unlock account. I want to delegate control to specific users to lock and unlock an account and to reset password only. These will be the only two rights that I want them to have.

The reset password is permission is clearly seen in delegate control wizard, but where should I find account lock/unlock permission?

Best Regards
SaDaT