Moving a PHP script from a local network onto a Website

While I'm working on a script that sits on a local server I've put it up on our own webspace.  The only thing is I seem to be have a problem with the folder locations

ie
require_once '/Classes/PHPExcel.php';

needed to be changed to

require_once 'Classes/PHPExcel.php';


i think the way to do this is have a configuration page where I can set up folder directions.   Like

$pathtoclasses = 'Classes';

the require once will then read

require_once $pathtoclasses.'/PHPExcel.php';

that can be changed easily when putting this software back on the server.   I've put this floder directions in db.php for know as I'll need to change the configuration on this page anyways.