My bet you'll require custom HI...
maybe a script that check domain registry key? just an idea..
https://www-secure.symantec.com/connect/articles/what-all-can-you-do-symantec-network-access-control
http://www.symantec.com/business/support/index?page=content&id=HOWTO11091
http://www.symantec.com/business/support/index?page=content&id=HOWTO55759