if i understand you correctly, you want to give a certain group of computers access to a file share.
you could add a script to each OU with group policy management (you need to install this application manualy). then go to the computer configuration (upper part), go to policies, windows settings, scripts (startup/shutdown).
you can add a simple script to each OU telling the computer wich drive to map. Be sure the active user can access the share and that the right share and ntfs rights are in place.