Too bad Toasty is no longer with us... I have found an elegant solution:
http://msdn.microsoft.com/workshop/networking/pluggable/overview/appendix_a.aspI have sucessfully launched the OP Direct tcp/ip host with a url of the form: opdirect://-Host
Working on an installer/uninstaller to make the registry entries now and and perhaps a middleman app so that I can encrypt IP addresses to pass to the -Client parameter so that IP addresses are not revealed on the game matching page.
Look for a direct tcp/ip game page on Dynaverse.Net soon!