pduino. comport object help.

dear all,

my goal is to make a simple synth in pure data and play it with a buzzer, attached to my arduino board.

i have my synth ready but how do i send it to my arduino board?
can i do it through comport object if yes how to route to which pin the synth should go? which converters to use? and finally which firmata do i need to load to arduino board in order to complete this task?

thank you