Rename help needed: "First Mid Last" to "Last, First Mid"

I've got thousands of folders for books and music which downloaded with the artist/author name as the folder name arranged this way:

A. C. Doyle
Bruce Springsteen

I want to do a batch rename so the folders appear as

Doyle, A. C.
Springsteen, Bruce

Some folders have middle initials/names, some don't. Is there a regular expression that can handle both cases? If not, can anyone help with a regex for each one separately?

Many thanks! I'm new to DOpus and regex...

Do a Regular Expression rename from

^(.+) ([^ ]+)$


\2, \1

Very nice! That did it.

Thank you!

Umm how do I access that feature for batch renaming with DOpus?
I have been using a separate tool but it doesn't have as much options.

Select some files, click the Rename icon in the toolbar and (if it opens in Simple mode) click Advanced.