help convert this SOAP request to Report Builder 2.0 query for XML data source

Question

I have a complex parameter to a web method in my .NET web service, and I want to query that web method with Report Builder 2.0 using SOAP. With soapUI, I get the following SOAP request for that web method:

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:qcr="MyNamespace">
   <soapenv:Header/>
   <soapenv:Body>
      <qcr:MyWebMethod>
         <qcr:MyComplexParameter><!--Represents a serializable class-->
            <qcr:Action>?</qcr:Action><!--string-->
            <qcr:ActionSortAscending>?</qcr:ActionSortAscending><!--Boolean-->
            <qcr:ActionSortOrder>?</qcr:ActionSortOrder><!--int-->
         </qcr:MyComplexParameter>
      </qcr:MyWebMethod>
   </soapenv:Body>
</soapenv:Envelope>

The only kind of Report Builder 2 queries I've worked with before were for web methods that took strings, integers, or other simple types as parameters. How would I go about writing a Report Builder 2 query for this SOAP request?

Sample Report Builder 2 query for web method with simple parameters:

<Query>
   <Method Name="MyWebMethod" Namespace="MyNamespace">
   <Parameters>
       <Parameter Name="MyStringParameter"><DefaultValue>foo</DefaultValue></Parameter>
       <Parameter Name="MyNumericParameter"><DefaultValue>3</DefaultValue></Parameter>
   </Parameters>
   </Method>
   <ElementPath IgnoreNamespaces="true">MyWebMethodResponse {}/MyWebMethodResult {}/Result</ElementPath>
</Query>