Restrict Regular Users From Shutting Down Their Workstation?

I work in a domain environment administering a large number of workstations running Windows 7 enterprise. I want to restrict regular users from shutting down their PCs so that I can perform remote administrative tasks without walking out on the floor and ensuring all 300 + machines are actually turned on. I do not have rights to the domain controller so I cannot assign by group policy. I can use psexec or ntrights to remove shutdown options from explorer but users can still initiate the shutdown command via cmd and pressing the power button on the tower still invokes a shutdown. Note: I am not talking about a cold shutdown i.e holding the power button (I can't actually do anything about that). So is there a way (perhaps in the registry) to disable the shutdown command for all users except the local administrator? I'll need to do this to over 300 PCs so if it can be done via script of command line that would be best