Setting up UCM on an internal server that can be accessed externally through a seperate webcache in

We have set up UCM on an internal server inside our firewall.  However, we want to be able to have our customers retrieve documents from it from the internet.  We have a seperate webcache already set up in our DMZ that we want to use to reverse proxy to the UCM server.  We have enabled the BrowseUrlPath functionality of UCM but there are apparentlly no notes that give clear examples of how the parameters need to be set in our situation. Does anyone have experience with this?

Thanks

Steve