I dont think you can use that script to make a pose file. It looks like the script does the work of plugging in the nodes to overlay a material on another.

They are not difficult to write, so you could package a script with your files.

 

attached ias a script that does that, requires an edit to name the overlay image and mask. It connects the same image to diffuse and specular , but it could be altered for seperate maps and masks.