I'm opening this thread in response to this closed thread

I'm looking to change the email subject of status update messages to show assigned status
E.X
Order Update #### Shipped

I tried the method in the reference thread but was not able to get it working, below is the 2 lines in my orders.php file,
PHP Code:
zen_mail($check_status->fields['customers_name'], $check_status->fields['customers_email_address'], EMAIL_TEXT_SUBJECT . ' [CP' . $oID.']', $message, STORE_NAME, EMAIL_FROM, $html_msg, 'order_status',$url);
            $customer_notified = '1'; 
How would I update this to accomplish the above.

TIA