Automated Open Cart Tracking Information

I require some code writing to automatically update tracking information on Open Cart. I originally started writing a PHP script which could be called via con job, but open to suggestions. There is a direct order module which places an order direct with the supplier, upon successful order placement, the order reference is updated in the order comments. The supplier has a feed available in XML with the order reference and tracking information. When the tracking information is updated, the status update email needs to be called to update the customer.