How to use require / include

[eluser]chaostheory[/eluser]
I am trying to load and use a class and create an instance of a class,
I dont want to use

Code:

$this->load->library('class');

is there are a way to use require_once , i keep getting errors when passing parameter like

$this->load->library('class');
$obj_soap = new Soap_download($get_dev_msg_amount);

it works fine in localhost when using require ("Soap_download.php") instead of this->load

any ideas?