Create a XML file from a trigger

Question

Here is the situation, I need to create a XML file every time a specific field from the table gets updated to "C" or "L". The Xml file needs to be like this:

<?xml version="1.0" standalone="yes"?>
<DATAPACKET Version="2.0">
  <METADATA>
    <FIELDS>
      <FIELD attrname="ID_COMAND" fieldtype="string" WIDTH="20" />
      <FIELD attrname="EVENT" fieldtype="string" WIDTH="1" />
    </FIELDS>
    <PARAMS />
  </METADATA>
  <ROWDATA>
    <ROW RowState="4" ID_COMAND="3721" EVENT="C" />
  </ROWDATA>
</DATAPACKET>

It's been very hard to find a way to do this, help me please.