I used RUNAS to achieve a switch in user. I found I had to also use ScriptIt (or AutoIt) to type the password (as RUNAS does not allow you to pipe the password into the command). The one thing I didn't like is the password was stored in a file somewhere which is a REALLY bad idea.

However the what I wanted to do was being done selectively and I knew who would be running the script and roughly when. So I put the password in a text file located in a hidden share and left it blank. Then the script would say, "This process has NOT been enabled. Please contact Mickey Mouse on 5551234!"

Mark