Android- how to launch lync 2013 from myapp

Hi 

I have a use case where I need to launch the Lync application ( Lync 2013 )conversation window from my application.

I need to start a Conversation Window with the emailID i provide in the intent.

my code :-

if (lyncDoesExist()) {

            Uri lyncUri = Uri.parse("lync://aaa.bbb@ccc.com");
            Intent myIntent = new Intent(Intent.ACTION_VIEW);

            myIntent.setData(lyncUri);

            myIntent.addCategory(Intent.CATEGORY_DEFAULT);
            startActivity(myIntent);

        }
This just starts the HubActivity ( the Lync application) .
It doesnot start the ConversationWindowActivity  (the chat window of the specific email id that I passed)
Am I missing anything in the code above ? I need to open the conversation window.
FYI - I also tried using Uri lyncUri = Uri.parse("sip:aaa.bbb@ccc.com"); but android says no activity found to handle the request.
Kindly help . I need this urgently.
Thanks,
Animesh.