schtasks

http://msdn.microsoft.com/en-us/library/bb736357(v=vs.85).aspx

Task scheduler

C:\Windows\system32>schtasks.exe /Create /TN sleep /SC ONLOGON /DELAY 0003:00 /T
R "c:\Windows\system32\rundll32.exe Powrprof.dll,SetSuspendState Sleep"