Export: Custom XML – list product SKU as often as pieces ordered

Hi,

we need to export a xml file for each order and then send it to our supplier via POST. Is this even possible directly in WP All Import (Export)?

As they require a very specific xml format, we need to list each product (the SKU) as often as it was ordered.
This is how it should like when product ABC was ordered twice and DEF once:

<products>
<artnr>ABC</artnr>
<artnr>ABC</artnr>
<artnr>DEF</artnr>
</products>

How could we achieve this?

Thanks!