How to set the Blend Tree parameter range in code?

I am creating an editor script that dynamically builds a Layer in a selected Animator Controller from a main directory and States inside the Layer from the sub-directories. Each created State contains a Blend Tree populated with the animation files in the directory.

I need to be able to set the Blend Tree parameter range equal to the number of files in the directory. Can't seem to find a way to access the parameter range thru code. Only seems accessible thru the editor.

If anyone knows a way to do this, you get mad awesome points!