i think to get by. your best bet is to assign an ip address for the 2nd nic (add ip address, and subnet mask, but no gateway or dns addresses)
then in that link i gave a while ago, set the priority of the 2nd nic above the 1st.
(remember on that step, where you don't see the advanced menu, to press ALT for the menus to come up)
NOTE: by setting the priority of the 2nd nic first, then multicast will attach to that nic, also, by not assigning a gateway, then you "route" for the internet becomes the 2nd nic. ( i think we can tweak some more stuff on the 2nd nic that aren't needed, but we need to get into that configuration first.)