Hi,
I had a look at the doc and description. Unfortunalty, it requires a lot of work on the c# code to get to this point of runtime binding, because of the way it's designed. That is without overriding with your own classes the input management, there is no direct way to have control over binding.
I would contact the Author and see if he would be willing to support Playmaker directly, because this is indeed a major task.
Bye,
Jean