Howto change the look of order confirmation

I put this code and copy to the folder that you said, but not works,

<?php
/**
*
* Define here the Header for order mail success !
*
* @package VirtueMart
* @subpackage Cart
* @author Kohl Patrick
* author Valérie Isaksen
* @link www.virtuemart.net
* @copyright Copyright (c) 2004 - 2010 VirtueMart Team. All rights reserved.
* @license www.gnu.org/copyleft/gpl.html GNU/GPL, see LICENSE.php
* VirtueMart is free software. This version may have been modified pursuant
* to the GNU General Public License, and as distributed it includes or
* is derivative of works licensed under the GNU General Public License or
* other free or open source software licenses.
*
*/
// Check to ensure this file is included in Joomla!
defined('_JEXEC') or die('Restricted access');
/* TODO Change the header place in helper or assets ??? */
?>
<table width="100%" border="0" cellpadding="0" cellspacing="0" class="html-email">
<td colspan="3">
<img src=<" www.secutorfight.com/images/logo-secutor-pagueseguro.jpg ">
<br/>
<strong><?php echo JText::sprintf('COM_VIRTUEMART_CART_MAIL_SHOPPER_NAME', $this->shopperName); ?></strong><br/>
</td>
<tr>
<td colspan="2">
<?php echo JText::sprintf('COM_VIRTUEMART_CART_MAIL_SHOPPER_SUMMARY', $this->cart->vendor->vendor_store_name); ?>

</td>
<td align="right"><span class="date"><?php echo $this->order->created_on ?></span><br/></td>
</tr>
</table>

You mention just "mail" all the time, that file is for "order mail success" like you see in comments at beginning of file. What mail are you referring to. You can just put overrides for all files in

components\com_virtuemart\views\cart\tmpl\

that have "mail_html" as part of their name, and put logo in them