Marketpress save order shipping information

I created a custom shipping plugin, in order to secure the shipment from the 3rd party carrier I am triggering the request inside the "order_confirmation" function (authorize-aim.php file)

* Runs before page load incase you need to run any scripts before loading the success message page

function order_confirmation($order) {
 //My request code here

When I make my request here I get information back from the 3rd party shipper, I would like to be able to save that information to the $order->mp_shipping_info['bol_url'], and then use it on the "manage orders" page.

I have attempted to save the information to the $order->mp_shipping_info array, however the information is not saving, can anybody help me with the code I would need to save the info to the order array.