wince calendar app

Question

Hello , I am doing calendar application on customised windows ce device....I am trying to add appointments using pimstore.... steps I followed: hresult hr = clsidfromprogid(progid,&clsid);

hr = CoCreateInstance(CoCreateInstance(CLSID_Application, NULL, CLSCTX_INPROC_SERVER, IID_IUnknown, (void **)&g_pUnknown); IAppointment * pAppt = NULL; then createItem().....

But i am getting "class not registered" for clsidfromprogid() May i plz know am I following the correct method....how to get the progid for clsidfromprogid()

thanks in advance