How to add php in header/footer?

[mox-]

Hi,
I made a little script called "template.php" that get the template from a .html file and gives me two variables ($tmpl_header and $tmpl_footer)
So I can use the same header/footer to determine the template of all my pages on a specific website (A kind of content manager)
How can I add php code to the header/footer of vbulletin so it will load template.php to let me echo the variables ?

Thanks

[mox-]

Sorry for that

I just found out about "hooks"