try changing this line to use require_once instead of virtual:
<?php virtual("////////////////////////////CSSMenuWriter/cssmw7/menu.php"); ?>
Also, I'm not sure why there are so many slashes in the path. You shouldn't need all of them. You can change it to this:
<?php require_once("CSSMenuWriter/cssmw7/menu.php"); ?>
You would also want to change in your site definition, the Links relative to option so that its document instead of site root.