set audio device to phone line

hi,
i am to develop code where in user calls from outside to his home phone connected to his pc to check his mails using TTS. Where I am stuck up at is the default output audio device are speakers. In my case the output has to be the phone line. How do I set the output to phone line and not speakers so that the speech is heard on phone and not speakers.
I have been able to get information that by getting the device Id you can set that. But guys how do I go about doing it. Please suggest me ways.

I Guess U Should Check out for some Customised ActiveX Controls Or already Some OCX's are there 2 help u Out.
in VB 6. EE

hi,
thanks a lot but I have seen c++ prgrms doingthe same kinda job. My problem is am not able to get hold of the corresponding dll's and ocx files in vb and the how to use them. if anyone cud pls help me out.