Logging in on Windows via VB.NET

You say I've locked my computer and I've a program which will auto-log me into the computer 5 minutes after the computer is locked. I have feeded the program with my user name and password. Now, 开发者_开发技巧I wanted to know, how do I make the program to auto-log me into Windows using VB.NET. Is there also any way to validate these details so provided?

There is no way for a program running on a users desktop to programatically log the user back into the desktop session once the desktop is locked