Hi Kaushik,
When opened via COM, TestComplete runs in silent mode by default unless you set its Visible property to True.
You can also force silent mode by assigning the value of 3 to the Manager.RunMode property of TestComplete's COM object.
As for your question about command line enhancement, we have an existing feature request for it, but I'm afraid there's no timeframe as to if/when this may be implemented. However, I've increased the rating of this feature request in our DB based on your post. In the meantime, you can use the COM approach to run test items silently.
