Actually, I think there MIGHT be a way.
Go to
www.sysinternals.com
Download PStools under utilities.
Install an NT based system on the remote computer.
Make a direct connection somehow and keep it open. (AIM, for example)
I forget how, but there's a way to get an IP for anything connected to you. Maybe it's net stat, I can't remember.
Inside the PStools package, there's a command prompt tool you can use to reboot a remote PC. (It can also kill remote processes...fun for pranks at work, fellow admins.)