You could experiment with the following code to get you started. Check the error return codes on these calls.
Code:
DCB dcb;
char Buffer[BUFFER_SIZE];
int iNoOfBytesRead;
hComPortHandle = CreateFile("COM1", GENERIC_READ, 0, NULL, OPEN_EXISTING, 0, NULL);
ErrorCheck = GetCommState(hComPortHandle, &dcb);
dcb.BaudRate = 1200; // change to your requirments
dcb.ByteSize = 8; // ..
dcb.Parity = 0; // ..
dcb.StopBits = 0; // ..
SetCommState(hComPortHandle, &dcb);
for(;;)
{
ReadFile(hComPortHandle, &Buffer, BUFFER_SIZE, (unsigned long*)&iNoOfBytesRead, NULL);
}