How to capture the stream that arrives to the SB

[Sasha]

Dear Sirs,

I'm working on application that should establish a voice conversation
through a voice modem, which have a speakerphone, with third party (a
telephone). When I use the Unimodem.TSP for playing or recording a
voice through the modem, I can work only in half-duplex mode (cannot
play or record in parallel). However, when I use a modem's
speakerphone, I can connect a microphone and a speakers to my sound
card, and I have a full-duplex functionality. What I need, is to
capture the voice which arrives from the modem's speakerphone to the
sound card, and to capture the audio (the voice) that is send from the
sound card, to the speakerphone back.

Where should I start in order to does that? I'm just a 3rd year CS
student, and have never deal with drivers development before,
especially not with the sound card drivers. But it seems that the
functionality that I need is a generic (and not a hardware dependent),
and should not be very complex for implementing.

Please help to the student, all tips and comments are welcome.

Thanks,

Sasha.