Hoping someone knows the answer....

I have a proxy (not BM) in place that both proxies and serves web
pages on
port 80. I am wanting to replace it with one of our BM 3.7 on NW 6
but cannot find a way to accomplish it (I know very little about BM).
the BM Server is listening on port 80 to proxy, accessing port 80 for
a web
request to the listening IP provides an HTTP Error. Status: 400 Bad
Request. Is this configuration possible?

More than 1000 clients are configured for the current proxy with their
pages set to the same IP and, of course port 80. All workstations are

protected, so client side changes must be done manually by the IT
crew. We
are hoping to avoid a major project.