Trying to automate Excel from C++

The background to this is that I am trying to do some winsock
programming in Excel. It is pretty simple. I am trapping the winsock
message by hooking into events for the Excel window and when it is a
winsock event I am calling a macro in Excel via COM.

There is a macro "callback(byval socketHandle as long, byval
socketevent as long)" but it doesn't get called. HR on the invoke is
S_OK:

// AptFIXcelSocket.cpp : Defines the entry point for the DLL
application.
//

#include "stdafx.h"
#include "AptFIXcelSocket.h"
#include <stdio.h>
#include <winsock.h>
#include <Objbase.h>

HHOOK hHook;
// This is an example of an exported variable
APTFIXCELSOCKET_API UINT WM_WINSOCK_MESSAGE=0;
WNDPROC callbackProc = NULL;
BSTR callbackProcName;
long currentWParam = 0;
long currentLParam = 0;

HRESULT AutoWrap(int autoType, VARIANT *pvResult, IDispatch *pDisp,
LPOLESTR ptName, int cArgs...) {
  // Begin variable-argument list...
  va_list marker;
  va_start(marker, cArgs);

  if(!pDisp) {
  MessageBox(NULL, "NULL IDispatch passed to AutoWrap()", "Error",
0x10010);
  _exit(0);
  }

  // Variables used...
  DISPPARAMS dp = { NULL, NULL, 0, 0 };
  DISPID dispidNamed = DISPID_PROPERTYPUT;
  DISPID dispID;
  HRESULT hr;
  char buf[200];
  char szName[200];

  // Convert down to ANSI
  WideCharToMultiByte(CP_ACP, 0, ptName, -1, szName, 256, NULL, NULL);

  // Get DISPID for name passed...
  hr = pDisp->GetIDsOfNames(IID_NULL, &ptName, 1, LOCALE_USER_DEFAULT,
&dispID);
  if(FAILED(hr)) {
  sprintf(buf, "IDispatch::GetIDsOfNames(\"%s\") failed w/err 0x%08lx
\n", szName, hr);
  ::OutputDebugString(buf);
  // MessageBox(NULL, buf, "AutoWrap()", 0x10010);
  // _exit(0);
  return hr;
  }

  // Allocate memory for arguments...
  VARIANT *pArgs = new VARIANT[cArgs+1];
  // Extract arguments...
  for(int i=0; i<cArgs; i++) {
  pArgs[i] = va_arg(marker, VARIANT);
  }

  // Build DISPPARAMS
  dp.cArgs = cArgs;
  dp.rgvarg = pArgs;

  // Handle special-case for property-puts!
  if(autoType & DISPATCH_PROPERTYPUT) {
  dp.cNamedArgs = 1;
  dp.rgdispidNamedArgs = &dispidNamed;
  }

  // Make the call!
  EXCEPINFO ei;
  UINT arg = 0;
  hr = pDisp->Invoke(dispID, IID_NULL, LOCALE_SYSTEM_DEFAULT,
autoType, &dp, pvResult, &ei, &arg);
  if(FAILED(hr)) {
  sprintf(buf, "IDispatch::Invoke(\"%s\"=%08lx) failed w/err 0x%08lx
\n", szName, dispID, hr);
  ::OutputDebugString(buf);
  //MessageBox(NULL, buf, "AutoWrap()", 0x10010);
// _exit(0);
  return hr;
  }
  // End variable-argument section...
  va_end(marker);

  delete [] pArgs;

  return hr;
}

BOOL APIENTRY DllMain( HANDLE hModule,
  DWORD ul_reason_for_call,
  LPVOID lpReserved
  )
{
  switch (ul_reason_for_call)
  {
  case DLL_PROCESS_ATTACH:
  {
  WM_WINSOCK_MESSAGE = ::RegisterWindowMessage("Apt Winsock Message");

  break;
  }
  case DLL_PROCESS_DETACH:
  {
  if( NULL != hHook )
  {
  AptCancelCallback();
  }

  break;
  }
  case DLL_THREAD_ATTACH:
  {
  // initialise
  CoInitializeEx(NULL, COINIT_APARTMENTTHREADED);

  break;
  }

  case DLL_THREAD_DETACH:
  {
  // initialise

  ::CoUninitialize();
  break;
  }
  }
  return TRUE;
}

APTFIXCELSOCKET_API long __stdcall AptGetMessageID()
{
  return WM_WINSOCK_MESSAGE;
}

// This is an example of an exported function.
APTFIXCELSOCKET_API long __stdcall AptSetupCallback(HWND excelWnd,
HINSTANCE excelInst, char * callbackfunction)
{
  if( NULL == hHook)
  {
  DWORD procID;

  // Hook in for the message
  hHook = SetWindowsHookEx
  (
  WH_GETMESSAGE,
  GetMsgProc,
  excelInst,
  GetWindowThreadProcessId(excelWnd, (LPDWORD)(&procID))
  );
  if ( NULL != hHook )
  {

  // callbackProcName = ::SysAllocString(_T(callbackfunction));
  }
  }

  return 0;
}

APTFIXCELSOCKET_API long __stdcall AptCancelCallback()
{
  if( NULL != hHook )
  {
  UnhookWindowsHookEx(hHook);
  hHook = 0;
  }

  return 0;
}

APTFIXCELSOCKET_API long __stdcall AptGetWParam()
{
  long wparam = currentWParam;
  char output[1028];
  sprintf(output, "Excel retrieved WParam %d \n", currentWParam);
  OutputDebugString ( output );
  currentWParam = 0;
  OutputDebugString ( "Cleared wparam \n" );
  return wparam;
}

APTFIXCELSOCKET_API long __stdcall AptGetLParam()
{
  long lparam = currentLParam;
  char output[1028];
  sprintf(output, "Excel retrieved LParam %d \n", currentLParam);
  OutputDebugString ( output );
  currentLParam = 0;
  OutputDebugString ( "Cleared lparam \n" );
  return lparam;
}

LRESULT CALLBACK GetMsgProc(int nCode, WPARAM wParam, LPARAM lParam)
{

  if (nCode < 0)
  {
  return CallNextHookEx(hHook, nCode, wParam, lParam);
  }

  __try
  {
  // Only interested in winsock messages
  LPMSG msg = (LPMSG)lParam;
  if( WM_WINSOCK_MESSAGE == msg->message)
  {
  IDispatch *pXlApp;
  IUnknown *pUnk;
  CLSID clsid;
  HRESULT hr = CLSIDFromProgID(L"Excel.Application", &clsid);
  hr = GetActiveObject(clsid, NULL, (IUnknown**)&pUnk);
  hr = pUnk->QueryInterface(IID_IDispatch, (void **)&pXlApp);
  pUnk->Release();

  VARIANT parm1;
  VariantInit(&parm1);
  parm1.vt = VT_BSTR;
  parm1.bstrVal = ::SysAllocString(L"FIXcel.xla!callback");

  VARIANT result;
  VARIANT LParam;
  VariantInit(&LParam);
  LParam.vt = VT_I4;
  LParam.lVal = msg->lParam;
  VARIANT WParam;
  VariantInit(&WParam);
  WParam.vt = VT_I4;
  WParam.lVal = msg->wParam;

  hr = AutoWrap(DISPATCH_METHOD, &result, pXlApp, L"Run", 3,
parm1,WParam,LParam);
  char output[1028];
  OutputDebugString ( output );
  msg = 0;
  VariantClear(&parm1);
  VariantClear(&LParam);
  VariantClear(&WParam);
  VariantClear(&result);

  pXlApp->Release();
  }
  else if( WM_TIMER == msg->message )
  {
  // call back into Excel
  // (*callbackProc)(msg->hwnd, msg->message, msg->wParam, msg-


  }
  }
  __except(EXCEPTION_EXECUTE_HANDLER)
  {
  // Do nothing
  }

  // Call the
  return CallNextHookEx(hHook, nCode, wParam, lParam);
}