Edit fields in Order Export

-- HikaShop version -- : 2.6.3
-- Joomla version -- : 3.5.1

I want to be able to use the Export button in Orders for my customer report. My client needs this as he wants to be able to specify the dates of orders for the export - NOT like mass actions which you have to set a period that is fixed.

However, the report that is generated has way too many fields that aren't needed. How can I specify which fields to show on this report?

I see no arrays that show the columns just references to "$productFields".

Where are the references to the columns?

Gotcha. For other users this is an example of code that won't throw any errors and deletes the columns:

unset($first[0], $first[1]);
	$export->writeLine($first);

unset($row->user_id, $row->user_cms_id);
		$export->writeLine($row);