Link Script in AD ~ PLEASE HELP ASAP~

Question

We have a new policy that has been handed down that I need to implement NOW, I have been told. I have written a VB script to do the changes required and it works fine. I have it currently in the GP Scripts logon, is there a parameter that I can set so that the progrma runs every 30 days or when the AD password expires? Or is there something in the Registry that I can modify so that the script will run every 30 days for every user?
Thank you