Using UNC paths with VPN

Hi, my name is John, I’m a network administrator. I have a firewall that is VPN capable. I’m using a program called ACT!, The program itself resides on the user’s computer and the database on the server which is behind the firewall. This program does not use tcp/ip when it searches for the database, It uses a UNC path. Q.How can I get this program to work across the VPN connection if it does not use tcp/ip?
Appreciate any help, thanks and happy holidays.
John

My email is john_agudelo@hotmail.com