In my wanderings, I came by a formerly commercial ActiveX control called Async Pro. It is available on
as a MPL control, so you can add it to your app for free, you just need to mention in the documentation that you are using.
It comes with lots of example code in various languages, and supports methods that will allow you to play and record WAV files (I haven't tried that part of the control yet).
It also comes with a terminal window (that doesn't flicker when updating like a text box will), Xmodem, Zmodem, TAPI, FTP, Telnet, etc., etc.
You can download the zip file, and you just need to use regsvr32 to register the APAX1.OCX control and you will be able to add it to Visual Studio's tool box. I think that you will get a lot farther, much faster using this control instead of the MSComm control.
pansophic