Mocking COM

using Excel = Microsoft.Office.Interop.Excel;
...
[Test]
public void MockExcel
{
  using (RecordExpectations recorder = RecorderManager.StartRecording())
   {
      Excel.ApplicationClass app = new Excel.ApplicationClass();
      app.Workbooks.Open(FileName, Type.Missing,Type.Missing, Type.Missing, Type.Missing,Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing);
//not mocked and starts Excel process
   }
}