Windows Server and Netbackup

I have several Windows 2003 servers that go through a reverse proxy and the
backups are failing with code 13 and 14 which is file read and file write
errors. I have read several docs from Veritas and they say it is a
networking problem. I think the backup is getting confused about the ip
address of the server. On our Unix servers we can put a REQUIRED_INTERFACE =
hostname in the bp.conf file but on Windows there is no bp.conf. I wanted to
know if this could be done on our Windows servers in the registry somewhere.