History Order id - Information field

Hi! I'm trying to develop a hikashop payment plugin...
I implemented it to recive a notification of my securey gateway provider, but now they change some specifications about their service... Before these changes I was be able to send them the ORDER ID and then they returns me this value to notify hikashop.

But now, they are not able to send me the ORDER ID and I can't identify the notification with my order.

I have been thinking about two alternatives:

1- Do manually the confirmation of the order with a ID transaction variable saved in table HISTORY field history_data, and when i recieve a new order, confirm payment manually identifying the transaction nº in history of and order, with that provided me the bank.

2- Starting saving the ID TRANSACTION generated by payment plugin in some field of the order, and then recive the payment notification, but identify the order with transaction nº and not the order id.

Some help please?

Um.... How can I store $idTransaction (generated in my payment_end.php) directly to history_data field...?
some code plizzzz