Override port on WebDav access links

We are running into a configuration issue after the switch from IIS proxy authentication to Kerberos. Specifically, the Portal Drive client stopped working because it seems that Kerberos is not supported, so we decided to setup a special port and leave IIS proxy in place just for Portal Drive users. However, the Access Links are now incorrect; we need to specify an alternate port for the WebDav access links, but I can not find anyplace to override that setting without making a more global change. Thanks in advance.

-jon