Hmm...you say you've created a custom template, how are you displaying it? Did you create a new php file for it or put it in an existing one? Unfortunately there is no "display a thread here" thing you can put in a template (if that's what you're asking). You'd have to have php code somewhere to query the database and do some processing on the result. You could get it from one of the existing vb files (although it's not easy to figure out exactly what you need), or maybe you could find a mod that does something similar and adapt it.
I'm a programmer and not really a site designer so maybe someone else has a suggestion. If you weren't planning to do a lot of programming for your custom page, maybe you'd want to look at
vbAdvanced CMPS (which had a free version last time I checked). It lets you build pages by arranging pre-written modules that do things like display the lastest threads from a forum, etc.