Check these similar threads:
https://www-secure.symantec.com/connect/forums/deploying-sep-121-startup-script
https://www-secure.symantec.com/connect/forums/ad-syncing-and-client-deployment
About installing clients with Active Directory Group Policy Object
http://www.symantec.com/docs/HOWTO26773
Creating a GPO software distribution
http://www.symantec.com/docs/HOWTO55429