Theme Horse

I have a custom PHP form (created outside of WordPress) at the root of my site that needs to look like the rest of the site. I can include the Interface Pro template header using:

<?php
define(‘WP_USE_THEMES’, false);
require(‘./wp-blog-header.php’);
include (TEMPLATEPATH . ‘/header.php’);
do_action( ‘interface_before_main_container’ );
?>

However, the code in header-extensions.php treats the pages as a 404 and sets the title to Page Not Found:

$interface_header_title = __( ‘Page NOT Found’, ‘interface’ );

How do I get the template to recognize this custom PHP page and display a title I define? I was able to add the page to the menu using the menu widget, and that displays the correct title.