Execute Program Using VB Script

I am writing a basic program with 3 buttons. I'd like to execute a setup program with one button, another program with another button, and exit with the third button. I can't seem to remember how to code for it, plus I'm using MS Visual Studio .NET 2003. I used to know how, but have forgotten. Any help would be appreciated. I've looked around on the web and seen that I can do: WinExec(); or CreateProcess(); but when I do them it comes up as errors. Thanks for the help.