Printing across network to Airport Extreme attached printer

Could someone please tell me how I can print to a Airport Extreme attached printer from across networks. Specifically, I have my Airport Extreme connected to the Internet, I have an HP printer attached to it via USB, and I can print from any PC, Linux, and Mac attached via ethernet wire or WiFi to the Airport. I also have a Safe@Home box that is also connected to the Airport that gives my work machine a VPN connection to work.

The problem is that I want to print to the printer from this work machine, but the Bonjour Printer Setup doesn't see it. I can ssh and ping the nodes on the other side of the Safe@Home box, and I know this has to do with the multicast packets not being retransmitted across networks, so what is the best option?