It looks like you are passing the reference to the page using: id_cms
So you can strip the id off the end of it with (assuming you add a dash and the id to the end of the links):
<?php
$_GET['Unique_ID'] = substr($_GET['id_cms'],strrpos($_GET['id_cms'],"-")+1);
?>
Then you can filter the recordset with the 'Unique_ID' url parameter which will have the value of the stripped off id from the end of the link.