Unlocking NT Workstation

I am writing an app that must issue a sendkeys. It will do this at all times of the day. Unfortunately, sendkeys does not work when the screen is locked. The user is still logged in, but the screen is locked. Is there an API call or other routine that can be made to unlock the workstation and lock it back when I'm done???????

PLZ!!!!

Thanks in advance!

If nobody knows how to do this... Does anybody have an app or something else that can log in? Then I could shell to that and cause a windows login?

Has anybody done this???? I'm desperate... plz... help....<G>