Setting exceptions to Quota calculations

Hello all, We are just starting a DSL business so we are getting ourselves familiar with FreeRadius. We are introducing packages that include unlimited traffic to certain domains such as youtube. Is there a way to set up our quota system to exclude traffic to youtube? If so, can we do it on specific users that sign up to the package and not everyone else? I realize that this might require some configuration on the router side, we are running a Cisco 7206/NPE-G1 if that helps. Appreciate your help Khalid