Hi,
You can simply add parameters in the url:
&filter_order=product_code&filter_order_Dir=asc
So the url will be:
administrator/index.php?option=com_hikashop&ctrl=product&filter_order=product_code&filter_order_Dir=asc
To force that any time without having to change the url, you can edit the view "product / listing" in the backend template and add the following code at the top:
<?php
if($this->pageInfo->filter->order->value != 'product_code'){
$app = JFactory::getApplication();
$app->redirect(JURI::base(true).'/index.php?option=com_hikashop&ctrl=product&filter_order=product_code&filter_order_Dir=asc');
}
?>