If you use Excel file in ADO, you cannot delete the line.

CSstring strFile=_T("C:\\temp\\sample.xlsx");
CStrings;
try
{
 CSstring strCon;
 strCon.Format(_T("Provider=Microsoft.ACE.OLEDB.12.0; Data Source=%s; Extended Properties=Excel 12.0xml"), strFile);
 con.CreateInstance(__uuidof(Connection)));
 con->Open(_bstr_t(strCon), '' , '' , adConnectUnspecified);

 _RecordsetPtrrs;
 rs.CreateInstance(__uuidof(Recordset)));
 rs->CursorLocation=adUseClient;
 rs->Open(_variant_t("SELECT* FROM [test$] WHERE [ID] = 'A1' ), con.GetInterfacePtr(), adOpenForwardOnly, adLockOptimistic, adCmdText);

 if(!rs->GetadoEOF())
 {
  rs->Delete (adAffectCurrent);
  rs->Close();
 }
}
catch(_com_error&e)
{
 s=e.ErrorMessage();
}