>Several years ago I wrote an application that used MSCOMM to retrieve data from a GPS device at 9600 baud.
>
>The device has been upgraded and now uses 230400 baud but I when I try to set MSCOMM to 230400 I get an error "invalid property value." Is it possible to set MSCOMM to accept 230400? If so how do I do it?
>
>Thanks in advance for any suggestions.

Seems you can set non-MSCOMM standard baud rates using the Windows API. Here's a VB6 example that should be a starting point:
http://www.mev.co.uk/pages/Support/VB-Baud.html