Run executable as a different user

Does anyone know the code to run an executable as another user?

I'm running a small vb program during login which queries computers using WMI. For the most part, it works fine running under the user who is logging in. However, there are a few calls which need to be made as a local admin...

Any ideas?

I have done sothing similar for a web app. I call a process to run, but I don't want it to use the IUSR_ account. What I did was I called an executable that then called a DLL I placed in COM+ (or MTS on NT4). Then in COM+, I designated the DLL to run as a different account.