[Phssthpok]

When saving books I specify the directory as {author_sort:re([.],)} to remove dots from the name, so that e.g. books by A.A. Milne are saved in "Milne, AA"

However, where there are multiple authors, I want only the first author, so I want to apply a second RE to remove everything after "&": something like {author_sort:re([.],):re(\&.*$,)}, but this is of course not valid.

What should I write to keep only the first author but with dots removed?