I have posted this in service too. But that is requesting a programmer to do that and I posted the topic here, just to chat about how easy is that to do? Or can we do it by ourselves instead of doing it by someone else and pay them.
I second that question as to why would you want to do that however, here is a converter link: http://www.phpbb.com/community/viewtopic.php?t=54908 I have not tested this but if I wanted a vb to phpbb converter, I would look on the phpbb site