有一个webservice，我需要访问此接口，下面是它的wsdl:

- <wsdl:operation name="retrieveUserUsageQuota" parameterOrder="subId">
  <wsdl:input message="impl:retrieveUserUsageQuotaRequest" name="retrieveUserUsageQuotaRequest" /> 
  <wsdl:output message="impl:retrieveUserUsageQuotaResponse" name="retrieveUserUsageQuotaResponse" /> 
  </wsdl:operation>

我从soap help文档中找到了一个c++的例子：
#include "stdafx.h"
#include < stdio.h>

#import "msxml3.dll" 
using namespace MSXML2;

#import "C:\Program Files\Common Files\MSSoap\Binaries\mssoap1.dll" \
         exclude("IStream", "ISequentialStream", "_LARGE_INTEGER", \
               "_ULARGE_INTEGER", "tagSTATSTG", "_FILETIME")
using namespace MSSOAPLib;

void Add()
{

   ISoapSerializerPtr Serializer;
   ISoapReaderPtr Reader;
   ISoapConnectorPtr Connector;

   // Connect to the service
   Connector.CreateInstance(__uuidof(HttpConnector));
   Connector->Property["EndPointURL"] = "http://localhost/DocSample2/DocSample2.asp";
   Connector->Connect();

   // Begin message
   Connector->Property["SoapAction"] = "uri:AddNumbers";
   Connector->BeginMessage();

   // Create the SoapSerializer
   Serializer.CreateInstance(__uuidof(SoapSerializer));

   // Connect the serializer to the input stream of the connector
   Serializer->Init(_variant_t((IUnknown*)Connector->InputStream));

   // Build the SOAP Message
   Serializer->startEnvelope("","","");
   Serializer->startBody("");
   Serializer->startElement("Add","uri:Calc","","m");
   Serializer->startElement("A","","","");
   Serializer->writeString("5");
   Serializer->endElement();
   Serializer->startElement("B","","","");
   Serializer->writeString("10");
   Serializer->endElement();
   Serializer->endElement();
   Serializer->endBody();
   Serializer->endEnvelope();
   
   // Send the message to the web service
   Connector->EndMessage();      

   // Let us read the response
   Reader.CreateInstance(__uuidof(SoapReader));

   // Connect the reader to the output stream of the connector
   Reader->Load(_variant_t((IUnknown*)Connector->OutputStream), "");

   // Display the result
   printf("Answer: %s\n", (const char*)Reader->RPCResult->text);
    
}

int main()
{
   CoInitialize(NULL);
   Add();
   CoUninitialize();

   return 0;

}
但是，不清楚soap以及wsdl等等规范，希望那位老大可以帮我改好上面的访问例子。实在是急事，没时间详细看soap和wsdl，等这个demo做出来我再细细研究，谢谢各位了。
或者帮我介绍一下，使用soap访问这个webservice时候需要如何写message...