Your question is very general, and lacking a script using this module (yes, I SuperSearch'd), the best I can do is point you to what looks like very complete documentation...http://search.cpan.org/~bbirth/Win32-SerialPort-0.19/lib/Win32API/CommPort.pm.

If you have specific problems that the docs can't answer, please try to refine your question further. BTW, you may simply be having problems naming the COM port? I know that sometimes "COM1" is required and other times "COM1:" is necessary...but this helpful hint does not mean that I've ever used the module, just ones like it in other languages.

Good luck,
welchavw