Hi,
The line you paste is the line for the header of the table.
You can change the "user_email" into another element of the table HikaShop user.
If you want to display an element of the Joomla user table ; it will require extra modification because the SQL request does not include this table.
Except the header which only provide the link for the sorting, the important line is the content line
<td class="hikamarket_order_customer_value"><?php echo $order->user_email; ?></td>
I will have to see how I could propose such link with the joomla user table but basically, I don't want to.
HikaShop have a "guest" account system where the customer does not have any Joomla account, creating a link with the joomla user table will work on several cases but not in all cases ; so if you use the guest checkout, you won't be able to display the username (or the user name).
So the most important is to know which data you want to display exactly (and from which table).
Regards,