I'm guessing you're trying to connect to an external device through a com port.
if not, ignore this :-p
I am trying to do the same thing and am having a lot of luck using the code that EvilSOB came up with.
here's the link
http://www.opserver.de/ubb7/ubbthreads.p...true#Post280484

I got someone to write me a c++ dll for it a few years ago, but never got the flexibility I needed from it.
good luck