I have files located in the following way:

public_htm/index.html

In index.html, i do an include : <?php include("includes/sidebar.html") ; ?> 

In sidebar.html, I need to include another file with require_once. This file is located here: /includes/PrayerSchedule.php

My question: how dow write the require_once in the sidebar.html file?  I use AddHandler so php is interpreted for HTML files.  Thanks.