xml order export, adding string in front of a variable

Hello

I use woocommerce and the XML order Export plugin, wich I adapted to the Output i Need. The following lines of code

'REMARK' => array(
					'@attributes' => array( 'type' => 'arbitrary_data' ),
					$order->get_item_total( $item_data, false ),
				),

produce this part in XML Export

<REMARK type=”arbitrary_data”>527.41</REMARK>

But what I Need is
<REMARK type=”arbitrary_data”>0;527.41</REMARK>

so I tried to just add the 0; in front of the $order->get_item_total( $item_data, false ),

like this

'REMARK' => array(
					'@attributes' => array( 'type' => 'arbitrary_data' ),
					'0;'$order->get_item_total( $item_data, false ),
				),

But that Ends in an errormessage, any one got an Idea how i can add the 0;