script and make the BBS run it as a scheduled event. Mystic has that feature, right?
Yes it does, but you are talking aver my head. :)
When you go to your dynamic DNS place, like no-ip.com, there'll be a help or howto page on remotely updating your IP. Yeah, you can use a special client, but you can also just make a web request. There are command line tools like 'wget' and 'curl' (for all OSes including Windows) that you can make the web requests with. The site will tell you what your unique URL is for updatingyour hostname, and you can put 'wget <url>' in a scheduled event. If it's too long, you put it in a batch file and call that from the scheduled event.
--- NE BBS v1.16 (linux; x64)
* Origin: NE BBS - nebbs.servehttp.com:9223 (21:3/193)