Scheduled task

Hi, in win2k, say that I am doing something in the DC then I want it to log off automatically after sometime while after I leave work, I checked the scheduled task but I found nothing relevant there. Is there anyway, I can log off, reboot and shutdown the computer using the scheduled task or even a batch file?
And if batch file is the only way, what to write in it and how to run the batch file (for logging off, rebooting and shutdown) if possible?