[TYPO3] Howto parse php page to content section

[typo3 at net-products.nl]

Hello
I have a menu item that direct to a php file:


page.20 = PHP_SCRIPT
page.20.file = fileadmin/template/main/invul.php

The page is now displayed above the site, and it should be in the content
section of the site

Question:
I have TS scripts that compose the website by a html template

How can I parse PHP_SCRIPT to a template above in the hierachy?

Or is there another way to solve is?