Ability to save individual pages to a new .web file

I'm currently working on a site and after creating more than 40 pages in my .web file I realise I need to split it into about 10 separate .web files, each of which will represent a sub-directory on the site.

I can't see any way to do this at present other than to save the whole 40 pages 10 times with the new filenames, and go through each of the ten, deleting almost all the pages one at a time.

Creating websites is often an organic process for me so it would be very helpful to be able to save individual pages to a new or separate .web file.

Linda