Automatically create Tasks in Windows Task Scheduler

A Windows Desktop Application that must run on Windows XP and Windows 7 (all versions). It must create a scheduled task. The task must run while the PC is logged off. The task must run under restricted user profiles; most especially on a domain when the logged in user is just a domain user (this user cannot install software or change the registry etc.) The code must use the [login to view URL] dll (this can be downloaded for free) I have some of the code done already and have attached it but I can't get it to work. The scheduled task I need to create is to sleep a PC. The task will do this by running an application called "psshutdown.exe" which can sleep a PC. This application "psshutdown.exe" can also be downloaded for free.