BleepingComputer.com: Batch script for ADDING directory to environmental path

I've tried creating a .bat file to add a directory to a Windows XP machine's environmental path using:

setx path "%PATH%;C:\Path\To\Directory" 

However it isn't working. From what I've read, doing this via the CLI only adds the variable to the path temporarily.

Is there a way to permanently doing it? Other than the obvious, longer approach of: My Computer>Properties>Advanced>Environmental Variables>Path>Edit

Anyone? This has to be possible from a scripting environment...