i added virtuemart_order_id
result on my csv is :
"invoice_number","virtuemart_order_id"
"1601045IVD02","5782"
"1601045IVD02","5782"
"1601045IVD02","5782"
"1601045IVD02","5782"
"1601045IVD02","5782"
"1601045IVD02","5782"
"1601045YJF01","5783"
"1601045YJF01","5783"
"1601045YJF01","5783"
"1601045YJF01","5783"
"1601045YJF01","5783"
"1601045YJF01","5783"
"1601045YJF01","5783"
"160104JBEH04","5779"
"160104JBEH04","5779"
"160104KPIG03","5780"
template :
<?xml version="1.0"?>
<csvi>
<template>
<settings>
<action><![CDATA[export]]></action>
<component><![CDATA[com_virtuemart]]></component>
<operation><![CDATA[order]]></operation>
<exportto>
<option><![CDATA[todownload]]></option>
</exportto>
<localpath><![CDATA[/home/mywebsite/public_html]]></localpath>
<ftphost><![CDATA[]]></ftphost>
<ftpport><![CDATA[]]></ftpport>
<ftpusername><![CDATA[]]></ftpusername>
<ftppass><![CDATA[]]></ftppass>
<ftproot><![CDATA[]]></ftproot>
<ftpfile><![CDATA[]]></ftpfile>
<export_email_addresses><![CDATA[]]></export_email_addresses>
<export_email_addresses_cc><![CDATA[]]></export_email_addresses_cc>
<export_email_addresses_bcc><![CDATA[]]></export_email_addresses_bcc>
<export_email_subject><![CDATA[]]></export_email_subject>
<export_email_body><![CDATA[]]></export_email_body>
<export_filename><![CDATA[testdenis.csv]]></export_filename>
<export_file><![CDATA[csv]]></export_file>
<field_delimiter><![CDATA[,]]></field_delimiter>
<text_enclosure><![CDATA["]]></text_enclosure>
<include_column_headers><![CDATA[1]]></include_column_headers>
<signature><![CDATA[0]]></signature>
<publish_state><![CDATA[1]]></publish_state>
<recordstart><![CDATA[]]></recordstart>
<recordend><![CDATA[]]></recordend>
<export_date_format><![CDATA[d/m/Y]]></export_date_format>
<export_price_format_decimal><![CDATA[2]]></export_price_format_decimal>
<export_price_format_decsep><![CDATA[,]]></export_price_format_decsep>
<export_price_format_thousep><![CDATA[]]></export_price_format_thousep>
<header><![CDATA[]]></header>
<body><![CDATA[]]></body>
<footer><![CDATA[]]></footer>
<language><![CDATA[fr-FR]]></language>
<splitorderline><![CDATA[1]]></splitorderline>
<ordernostart><![CDATA[5778]]></ordernostart>
<ordernoend><![CDATA[]]></ordernoend>
<orderlist><![CDATA[]]></orderlist>
<orderdaterange><![CDATA[]]></orderdaterange>
<orderdatestart><![CDATA[]]></orderdatestart>
<orderdateend><![CDATA[]]></orderdateend>
<ordermdatestart><![CDATA[]]></ordermdatestart>
<ordermdateend><![CDATA[]]></ordermdateend>
<orderstatus>
<option><![CDATA[S]]></option>
</orderstatus>
<orderpayment>
<option><![CDATA[]]></option>
</orderpayment>
<order_address><![CDATA[BT]]></order_address>
<ordermanufacturer>
<option><![CDATA[none]]></option>
</ordermanufacturer>
<ordercurrency>
<option><![CDATA[47]]></option>
</ordercurrency>
<orderpricestart><![CDATA[]]></orderpricestart>
<orderpriceend><![CDATA[]]></orderpriceend>
<orderuser>
<option><![CDATA[]]></option>
</orderuser>
<orderproduct>
<option><![CDATA[]]></option>
</orderproduct>
<groupbyfields><![CDATA[{"name":["virtuemart_order_id","invoice_number"]}]]></groupbyfields>
<sortfields><![CDATA[]]></sortfields>
<use_system_limits><![CDATA[0]]></use_system_limits>
<max_execution_time><![CDATA[]]></max_execution_time>
<memory_limit><![CDATA[]]></memory_limit>
</settings>
<template_name><![CDATA[testdenis]]></template_name>
<advanced><![CDATA[0]]></advanced>
<action><![CDATA[export]]></action>
<frontend><![CDATA[0]]></frontend>
<secret><![CDATA[]]></secret>
<log><![CDATA[0]]></log>
<lastrun><![CDATA[2016-02-15 16:32:33]]></lastrun>
<enabled><![CDATA[1]]></enabled>
<ordering><![CDATA[0]]></ordering>
<fields>
<field>
<field_name><![CDATA[invoice_number]]></field_name>
<xml_node><![CDATA[]]></xml_node>
<column_header><![CDATA[]]></column_header>
<default_value><![CDATA[]]></default_value>
<enabled><![CDATA[1]]></enabled>
<sort><![CDATA[0]]></sort>
<cdata><![CDATA[1]]></cdata>
<ordering><![CDATA[2]]></ordering>
</field>
<field>
<field_name><![CDATA[virtuemart_order_id]]></field_name>
<xml_node><![CDATA[]]></xml_node>
<column_header><![CDATA[]]></column_header>
<default_value><![CDATA[]]></default_value>
<enabled><![CDATA[1]]></enabled>
<sort><![CDATA[0]]></sort>
<cdata><![CDATA[1]]></cdata>
<ordering><![CDATA[1]]></ordering>
</field>
</fields>
</template>
</csvi>