Login Lab Workstations from Teacher’s

I have 65 computers (W2K) running on a W2K3 network in a school. I’d like to figure out a way that the computer teacher, from her computer, can force the other computers to login and be ready for the next class; the littlest kids have trouble waiting for the login time. Each class has their own user names and passwords (big kids have individual ones). It seems like I should be able to write a batch file to do this, one for each class. Can this be done, and if so, how?