How to properly process the unloading of counterparties from 1C?

Question

1C-Bitrix

Hello!
Essence of the question. An additional field was added to the unloading of counterparties from 1C. I ask for tips on how to properly process the upload on the site, so that when uploading from 1C, the additional property that was added for uploading should be recorded in the user field.
Tell me which direction to go. Maybe someone has already done this and will share the solution. But in general, a hint will suffice.

Answer 1

Figured it out myself. The CSaleOrderLoader method solved the problem, extended the class to fit your needs.