Include of External Php Files in Subforums Headers or in Threads

[Rockeru]

I would like to include some php files in some subforum headers or if this is not possible in threads.

The php code would be something like:

PHP Code:

<?php include 'http://sites_path/ssi.php'; ?>

Does anyone know how if it is possible to do this with VBulletin
and were should the include be made?