It should be possible to do with some Photoshop scripting.
PM already allows you to run Photoshop droplets on selected files. The droplet can execute any Photoshop script. I am not sure if it's possible for the script to take as input the files parsed to it by the droplet, but if yes, you would "just" need to create a script that takes the parsed files, makes a new document and puts them in layers. Look at "Load Files into Stack.jsx" in your Photoshop scripts folder as the basis of your script.
You would then create a PS action invoking the script, save it as a droplet, and use PM's Send to droplet.
