WordPress MU

I want to use
<?php get_header();?>
<?php get_sidebar(); ?>
<?php get_footer(); ?>
in my php file;
So I put the
<? require('./wp-blog-header.php'); ?>
at the beginning of the page to make sure the get_header function work properly.
I want to know which other two files I have to add along with wp-blog-header.php for using get_sidebar and get_footer?
Because now it doesnt load the footer and siderbar.
Thanks!

What does your php file do? It might be easier to write it as 1) a template for your Wordpress theme, or 2) a plugin.

Thank! I will try template.