vB Forum and CMS Network

[AleXanniX]

Hello
i'm Italian, so sorry for my bad english.
I decided to create a vb. forum network in my site in this way
mysite.com <- vb cms home page, with news about all portal in my site
example1.mysite.com <- vb cms about a specific topic
example2.mysite.com <- vb cms about another topic
forum.mysite.com <- my vb 4.x forum
example3.mysite.com <- a forum of one of my vbforum, for exmple mysite.com/forum/forumdisplay.php?f=1 -> example3.mysite.com, and mysite.com/forum/showthread.php?t=3 -> example3.mysite.com/showthread.php?t=3, but last topics and number of Threads and posts must be displayed in forum.mysite.com, and users online on example3.mysite.com must be seen in forum.mysite.com user list too.

How do i do it?
If i use just a database, how many licenses must i buy?