Selecting a getting the previously selected data

Thanks but it doesn't seem to work.

Here is the code i have used,

HRESULT hr = S_OK;

  CComPtr<IModelDoc2> pModDoc;

   hr = pSwApp->get_IActiveDoc2(&pModDoc);

CComPtr<ISelectionMgr> pSelMgr;

  hr = pModDoc->get_ISelectionManager(&pSelMgr);   

  long l_Ind=1,l_Mk=-1;

  CComPtr<IDispatch> pDisp;

  hr = pSelMgr->GetSelectedObject6(l_Ind,l_Mk,&pDisp); //Getting all the selected sketch points

  if (FAILED(hr) || !pDisp) return E_FAIL;

  CComPtr<IModelDocExtension> pModExtn;

  hr = pModDoc->get_Extension(&pModExtn);

  CComVariant Var1;

  hr = pModExtn->GetPersistReference3(pDisp, &Var1);

  hr = pModDoc->ClearSelection2(VARIANT_TRUE);

  long Err;

  CComPtr<IDispatch> pDisp2;

  hr = pModExtn->GetObjectByPersistReference3(Var1, &Err, &pDisp2);

// here i would like to know how do i select all the sketch points at once