DT Pro Server Intranet/Internet problems

I would like to use DT Pro as a makeshift file server as well as having search capabilities for both Internet (WAN) and LAN users. I use an excel spreadsheet with information and links to files stored in DT. (myip:port/filename.pdf.zip?id=697432&action=view for example).

This setup works great if I use the WAN IP for outside user or if I use the bonjour supplied LAN IP for my intranet users, but not both (LAN users cannot access the DT server using the WAN address and vice-versa obviously)

I would prefer to publish the WAN address based link and have the LAN users be able to use that same link. Is there a way (router config maybe) to forward LAN user requests using the WAN IP to look on the local network (at the bonjour or machine IP)?

Any thoughts or help you can provide would be much appreciated. If I cant resolve this I will have to create 2 different links for each file that would only work based on the users location in or out of the local network.

Thank you

This should be possible but in the end it depends on the router.