Joomla + Virtuemart = create xml for expedition webservice

Hi I need help to create automatically an xml file for the expedition company here you have the xml example: -<order_update>   <order_number>000001</order_number> - <client_info>   <client_id>0</client_id>   <name>Bob Lemoche</name>   <email></email>   <ccard>visa</ccard>   <credit_conf>0000000</credit_conf> -<shipping_address>   <name>Bob LeMoche inc.</name>   <address1>123 shipping street</address1>   <address2>suite 101</address2>   <city>Montreal</city>   <state>QC</state>   <country>can</country>   <postal_code>H1H1H1</postal_code>   </shipping_address> -<billing_address>   <name>Bob LeMoche inc.</name>   <address1>123 shipping street</address1>   <address2>suite 101</address2>   <city>Montreal</city>   <state>QC</state>   <country>can</country>   <postal_code>H1H1H1</postal_code>   </billing_address>   </client_info> - <items> -<item>   <sku>1234</sku>   <qty>12</qty>   <price>10.25</price>   </item> -<item>   <sku>5678</sku>   <qty>5</qty>   <price>1.25</price>   </item>   </items> -<fees> -<fee>   <name>FRGT</name>   <amount>10.44</amount>   </fee> -<fee>   <name>TPS</name>   <amount>6.48</amount>   </fee> -<fee>   <name>TVQ</name>   <amount>10.18</amount>   </fee> -<fee>   <name>HST</name>   <amount>0.00</amount>   </fee> </fees>   <order_total>156.35</order_total>   </order_update>