exclude the URLs for the certificate revocation lists

TMG 2010 (latest updates dates back to Dec 22, 2012)

Win2k8 R2 SP1, 6GB RAM

i'm using VAMT2.0 for our Office product activations and when IE is configured to use a proxy, VAMT doesn't work. only if i remove the use of a proxy server does VAMT works.

i saw this article Windows activation fails and method 2 says "to exclude the URLs for the certificate revocation lists (CRLs) from the requirement for Basic authentication"

how does one exclue a URL from basic authentication? i can create firewall policies to exclude or allow certain sites but "exclude from basic authentication"?