We have a site were all users are using Client Trust successfully to
authenticate and get proxy access. However, there are a couple of Windows
servers, that do NOT have the Netware Client loaded, that need internet
access through the Border proxy (ie, to get virus .dat updates).

Whats the easiest way to create an exception for these servers so they do
not need authentication/client trust at all?

I have not used BM for about 3 years (moved to Squid, sorry :), but one of
our sites is having issues.