Parsing webservice parameters

I would like to retrieve the parameters I send to a webservice from the result handler.  The webservice is being called multiple times in succession, so I cannot refer to the WebService object because it will only have the parameters for the last call.

In the result handler I have this in the event.token.message.body:

<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:s="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <SOAP-ENV:Body>
    <tns:MyWebServiceMethod xmlns:tns="http://myServer/myWebService">
      <tns:RowNumber>
        2
      </tns:RowNumber>

      <tns:OtherParameters>
         ...
       </tns:OtherParameters>

    </tns:MyWebServiceMethod>
  </SOAP-ENV:Body>
</SOAP-ENV:Envelope>

I really just need to get the value for RowNumber.  Thanks in advance.