How to detect DTMF after playing wave file using MCI

[Guest_imported]

I am developing Voice Mail System for one of the projects. But I am facing a problem that once I played the file on the phone line using MCI, my lineMonitorDigits functions does monitoring but application doesnt detects digits. If I use NOTIFY flag while playing file using MCI then while file is playing application can detect digits.

 

[tedsmith]

I am also trying to write a voicemail application. I use AT commands thru the MsComm control to control the modem OK and Playsound API to play the wave files.
The audio output of the modem is connected to the soundcard input(line in to record) and the soundcard output fed to the modem audio input via a 20db attenuator.(wave file to play)
Do you have a way of using the digital line to the modem to produce audible sound?
My problem is how do I detect the DTMF tones?
regards Ted
please reply to tedsmithau@Yahoo.com.au