How to use codeigniter helper, model, library etc from a php file

[eluser]cinewbie81[/eluser]
The following is my code:

Code:

<?php
if (!defined('BASEPATH')) exit('No direct script access allowed');

class Test extends Controller {

    function Test()
    {    
        parent::Controller();
        $this->load->helper(array('url','form'));
    }

    function index()
    {    
         exec("nohup php /var/www/myproject/backendprocess.php > /dev/null &");
    }
}
?>

backendprocess.php

Code:

<?php
  // How to use codeigniter helper, model, library file here ???
?>

My question is: How can i call codeigniter helper, model, or library file in my backendprocess.php ??
I try

Code:

$obj =& get_instance();            
    $obj->load->helper(array('url', 'globalsetting'));

it's not working though

Just for you all information, backendprocess.php.php is located in the same path as /system folder. Hope to hear from you guys soon, thanks