Forum: Radiant CMS php equivalent

I'm wondering what the Radiant equivalent is for php include. For
example, <?php include("violet.txt"); ?>

I'm trying to duplicate this page I've created as a php file:
http://twicebakedfx.com/temp/product/ in Radiant and the tooltip (when
you mouse over the purse thumbnail) is a .txt file added with a php
include and some external javascript like so:

<a href="http://store.michebag.com/a/bags/original/MB5131.jpg"
title="<?php
include("http://store.michebag.com/a/bags/tooltips/MB5131.txt");
?>"><img src="http://store.michebag.com/a/bags/140/MB5131.jpg"
width="140" height="122" alt="Jean MB5131 | December 2011" /></a>

Any ideas? I'm not personally familiar with the tags, and our programmer
is gone.

Thanks.