I don't see the problem.
The way to go is IMHO as follows
  • Create a Computer Policy
  • Set this policy on a OU above the computers where you want to run the script on
  • Create a Global Group
  • Populate goup with Computers you want to run the script on
  • Edit the Security settings
  • Remove the "Authenticated Users"
  • Add the Global Group to the Security settings
  • Give "Read" and "Apply Group Policy" permissions

Take a look at this: Group Policy Computer Startup Software Installation Script
and at this: Group Policy Object (GPO) Rules. where I want to quote this:
 Quote:
As per Microsoft recommendation you should remove *Authenticated Users* group and create a new Group and add all members to this group and then use Group Policy Filtering technique.