Esther,
Layers list is the only thing you can save and group like that in browser. It will automatically increment the number tho. So no real grouping and no way  to have them replace the existing ones. Layers List are also hard to manage w/o the dcg plugin which can let you add notes. You can cutnpaste in the shader room tho. You might try taking what you like from one file, (copying) then paste it into the other file, then copynpaste into the layers list what you want. You can drag a shader once you get it the way you like to the tray w/ saving the car file tho. Personally, shader domains are easier to deal with and manage, but they got other draw backs. This is an area that needs some work. Just being able to select all in the shaders area and group would help alot.

No need to think outside the box....
    Just make it invisible.