Hi,
I am writing code in c++ for sending and receiving messages through
ports. I have written code for opening port as

hComm = CreateFile(portname,GENERIC_READ | GENERIC_WRITE, 0,
0,OPEN_EXISTING,0,0);
this is done , but
Now I need to send the message to be send to Port. also need to get reply from port as a message.
How can I do this? Shall i use any existing dll for this? if yes which one? Does I need to do with hardware ( like shortning of pin..)
I need to do it on single PC.
The help is strongly appreciated. please also suggest some links which i can go through...

Thanks
Mukesh :)