#include <conio.h>			// kbhit()
#include <XXX>
#include <XXX>
// etc.

int main(int argc, char* argv[])
{
  // type definitions

  // open serial port as COMXX

  // establish whether 5 or 7 bits through argv[1], and pick mask

  while (!kbhit())
  {
    ReadFile(hSerial, sInBuff, 1, &dwBytesRead, NULL);
    if (dwBytesRead > 0)
    { 
      // apply masks
      // parity check
      // LRC calculation
      // string formatting
    }
  }
  // print results
  CloseHandle(hSerial);
  return 0;
}