Multiple Site Manager: Same site, multiple domains

I am hosting multiple websites on a locally networked server which will be serving publicly. We are using Multiple Site Manager to handle these sites, but an issue has come up. Anyone on the local network cannot visit the domain name for the site because of a nat loopback error and we are unable (security & bureaucratics) to alter our local DNS entries to adjust for this.

I am looking for a solution for this. Is there a way to effectively have multiple entries or an array within : $assign_to_config[‘cp_url’] = ‘http://websrv0/admin.php’;

the only other option that I can tell would be to mirror the website as another MsM site with different bindings and domain settings in the admin and index files. This very much feels like reaching around the elbow however, and I am looking and hoping for a different option.

Thanks!