Hi,
I would study how I made it for Photon, or NGUI. it's using a monobehavior that implements the messages, and then forward it to playmaker as an event.
Also, study input.touch package is you have input.touches, it will give you a very good base if easy touch is using delegates.
so in essence, the key is to forward the event, not "listen" to it, you "listen" to it with a normal script that in turn forward to PlayMaker.
bye,
Jean