Opencart Iinvoice Currency -

hi there i'm facing problem opencart 1.5.5.1 .

the currencies i've set working checkout process don't want changed.

after order , i'm going print invoice need change currency fixed 1 (usd of course) coz the forwarder need invoice in usd fot international shipments.

the ideal way switch between checkout currency , usd when generating invoice printed.

i've found , modified vqmod work current opencart version

<modification>     <id><![cdata[invoice in base currency]]></id>     <version><![cdata[1.0.0]]></version>     <vqmver><![cdata[]]></vqmver>     <author><![cdata[abhishek tiwari]]></author>     <file name="admin/controller/sale/order.php">         <operation>             <search position="replace"><![cdata['price'    => $this->currency->format($product['price'] + ($this->config->get('config_tax') ? $product['tax'] : 0), $order_info['currency_code'], $order_info['currency_value']),]]></search>             <add><![cdata['price'    => $this->currency->format($product['price'] + ($this->config->get('config_tax') ? $product['tax'] : 0), $this->currency->getcode(), $this->currency->getvalue()),]]></add>         </operation>         <operation>             <search position="replace"><![cdata['total'    => $this->currency->format($product['total'] + ($this->config->get('config_tax') ? ($product['tax'] * $product['quantity']) : 0), $order_info['currency_code'], $order_info['currency_value'])]]></search>             <add><![cdata['total'    => $this->currency->format($product['total']+ ($this->config->get('config_tax') ? ($product['tax'] * $product['quantity']) : 0), $this->currency->getcode(), $this->currency->getvalue())]]></add>         </operation>         <operation>             <search position="after"><![cdata[$total_data = $this->model_sale_order->getordertotals($order_id);]]></search>             <add><![cdata[foreach ($total_data &$total) {           $total['text'] = $this->currency->format($total['value'], $this->currency->getcode(), $this->currency->getvalue());         }]]></add>         </operation>     </file> </modification> 

as long understand should default store currency generate invoices it's not working me. , right base store currency eur if try change usd amounts displayed in stats not being converter change currency symbol!