clicks via serial port emulating mouse

Hello,

I have a PTB-2 code which takes feedback from a mouse (using GetMouse).
I want to adapt it to be able to take the feedback from click-pads
which feed into the serial port of the computer running PTB.

Additionally, I'll want to send event triggers using PTB via the serial
port of the computer to the MEG acquisition.

Does anyone have any idea about how to go about doing this?
I have been experimenting with PsychSerial but have not been able to
make much headway. I am not even sure that is the correct way to
proceed.

The software has been used successfully (by somebody else) with EEG
using the following command (and a few lines more)
printerport=digitalio('parallel','LPT1');

and then sending information via printerport.

thanks,
sameer