no, a button can't do "2 things".
ie if it has a Procedure, or URL attached then it's going to make a call to that Procedure or URL. If it doesn't have a Url or Proc then it'll call the browse itself, and run the Server Side code for the button. But it can't do both.
(Well strictly speaking it could do both - but the order would be undetermined - which would make it pretty useless for you.)
Cheers
Bruce