How to add a property to the unloading of orders?

Question

1C-Bitrix

Hello Toaster!
I have been fighting for several weeks with the issue of exchanging orders with 1C UT.
The 1C programmer asks me to add a new parameter (product code) to the order.xml file.

<ТоварнаяПозиция Каталог="3cea3d7e-33f2-4e4f-b6ac-1f798ce39812" Товар="6105009a-0365-11e4-b9d9-005056c00008" Единица="" Количество="1.00" Цена="169.0000" Сумма="169" Описание="Рогатка &quot;МВ&quot;, средняя (без упора)"/>

You need to add a new property (product code) to this tag.
Help me to understand.