it requires doing some digging in the code.
in the UE behavior code on the contact us page, there will be a line similar to this:
include("webassist/email/waue_contactus_1.php");
if you look in the file referenced: webassist/email/waue_contactus_1.php
there will be another line that refers to the template page:
$MailBody = $MailBody . (GetFromPage("templates/Center.php"));