首先导入类型库
#import "xxx.dll"

 CoInitialize(NULL);                //notice
 _clsNewDentalEditor *p;         //declare the pointer
 HRESULT ht = CoCreateInstance(CLSID_clsNewDentalEditor, NULL, CLSCTX_INPROC_SERVER, IID__clsNewDentalEditor, (void **)&p);
 CComVariant Param1, Param2, Param3, Param4;  //notice
 ht = p->Exec(&Param1, &Param2, &Param3, &Param4);
 CoUninitialize();