I have a project where the Local Structure setting is:
[Html in web/, images/other files in web/images/]

This works fine except that many of the original filenames of images have
strange characters like %, #, or ; that makes post-processing the files
difficult. I thought to use a User-defined structure to rename the files as a
MD5 Url hash + extension (%M.%t), but how can I have that only apply to
non-html files? I still want the html files to keep the original names as much
as possible.

Also, when using User-defined structures, how do I still define the structure
as such?[Html in web/, images/other files in web/images/]
Or do I have no choice to to either have all ones in one directory or have
hundreds of folders using %h%p/?
Thanks