Running NW5.1sp5 BM3.6sp1a w/c02 updates

Are there plans (or does a newer version do it) to allow
filtering/exceptions by DNS Name instead of only by IP address?
Specifically this relates to update antivirus dats from NAI, they use
service for the ftp sites and it is always changing. go ahead try it,

ping ftp.nai.com then do it again from the same machine, you can get
different IP each time, not even in the same subnet even. I know a
solution is to allow from a specific machine to ftp to any, but I
prefer a limit to ftp.nai.com.

We script to check for new dats nightly on a couple linux boxes,
one will succeed because at that moment it resolved to an IP in the
subnet we openned for it, but the other will fail because it resolved
different IP.

Thank you,