I have a 3 column layout with a header and footer. I would like to put miniBB in middle column and leave rest of pages the same so it looks like the rest of the pages.

put your code on main_header.html ^_^!

Well K3Exe, there is already a matter of exactly how his side is up :) And if you yourself not being able miniBB incorporate into your own design ... Paul offers his service :)

But you're right, everything is what defines between $includeHeader and $includeFooter .. presents miniBB ;-)

You just need to split your template into two parts, then copy them respectively to templates/main_header.html and templates/main_footer.html. When executing, miniBB will "put itself" between those codes.