OWA through a Firewall?

Wondering if it’s possible to run OWA either through or on our firewall server. We are running NT 4 SP6a on all servers, Exchange 5.5 SP3 on the mail server, and Gauntlet 5.5 as our firewall.

As a test I installed IIS 4.0 on a BDC and setup OWA on that. Works great on our internal network, but cannot be accessed from other subnets or the internet.

Is there any way to make this work – install on the firewall?….other solution?

Any help would be great…