register.php question

[Mighty]

I have an existing registration form for a portion of my site. I have recently installed vB and want to add an optional section of the registration form that allows the users to also register for my vB at the same time. I'm already collecting the e-mails of the users, so they just need to add a username and password.

So basically, I want to feed the register.php the variables from my form instead of the one used in register.php.

Can someone point me in the right direction for accomplishing this? I am pretty familiar with PHP, but fairly new to vB so I don't know where to start in the register.php file.

If there is an existing post or resources on this, that would be helpful as well. I tried looking at the phpNuke integration posts, but that solution is more geared towards sharing the same database and I'm not using phpNuke.

Thanks for your help.