VBBS/VADV doesn't have a way internally to telnet out. I used to use the Citrisoft telnet door to accomplish it back when I was running an OS/2 machine for the BBS and Windows NT for the TWGS. The final version of the door suite, which was released as freeware, had both OS/2 and Win32 binaries but I am not entirely sure how well the DOS version of VBBS/VADV will be able to use the Win32 binaries if that is the host OS; they pre-date Door32 as I recall. The OS/2 version worked great. The OS/2 version of VADV was another story.
The closest thing to an official place for VADV support these days is
http://www.at2k.net, but just send him or her my way if you like. I have the citrisoft stuff backed up on CD and I believe I still have the scripts as well. thistledownsql on yahoo