C / C++ / MFC

typedef HGLOBAL HMYOBJ;

// exported DLL function
HMYOBJ GetDLLObject()
{
  HGLOBAL hObj = GlobalAlloc(GPTR, sizeof(CMyClass));

  // initialize it
  CMyClass *pClass = (CMyClass *)hObj;
  pClass->Init();

  return (HMYOBJ)hObj;
}

...

// another exported function
BOOL UseDLLObject(HMYOBJ hObj)
{
  CMyClass *pClass = (CMyClass *)hObj;
  return pClass->DoSomething();
}

void DestroyDLLObject(HMYOBJ hObj)
{
  CMyClass *pClass = (CMyClass *)hObj;
  pClass->CleanUp();
  GlobalFree(hObj);
}
...

// here's how the caller would use the DLL
HMYOBJ hObj = GetDLLObject();
BOOL ok = UseDLLObject(hObj);
DestroyDLLObject(hObj);