I'm editing comic pages with layers - "background", "foreground", "lineart" and "over lineart".

I have a Photoshop action that includes a Mode->Bitmap command, which requires the image to be flattened. I need this part of the action because I use the Halftone Screen method of reducing the greyscale image to bitmap on the "background" layer, creating a certain effect. I am pretty sure there is no filter or anything else that gives the same effect. After the mode is changed to bitmap, my action changes things back to greyscale for further changes.

This poses a problem. I only want to do the bitmap mode change on the background layer, and after I do the change I want to restore the layer structure as it was - with the foreground, lineart and over lineart layers back above the now-halftoned background.

My current method of saving these layers and restoring them is clumsy. My action is able to automatically save the "foreground" layer by selecting it, cutting it, then pasting it back in after the mode changing is over. But, for the "ink" and "over ink" layers, I have to manually cut these layers, paste them into a new document, and later re-cut and re-paste after running my action. This is so clunky!

What I would like to know is if it's possible to set aside my layers in an automated way, and then bring them back in, also in an automated way.

An ugly (but functional) solution would be to replicate my actions of creating new documents and pasting them temporarily there, but I don't think Photoshop allows you to do things outside of your current document with an action. It seems to me that the only way to do what I want is to use the "hack" of incorporating the clipboard into the action as a clever hack, but that leaves me stuck as I have two more layers that can't fit onto that same clipboard.

Help or suggestions would be appreciated. I can keep on doing it manually, but to have a comprehensive action would save me a ton of time.