Try this:
Code:
Star Wars\s+-\s+(\[(?P<series>.+?)(\s+(?P<series_index>[0-9]+))?\]\s+-\s+)?(?P<title>[^(]+)\s+\(by\s+(?P<author>[^)]+)\)
There seems to be no way to set a tag so you will have to set the tag manually after importing your books.
EDIT:
You can set the tag by setting Preferences / Adding books / Tags to apply when adding a book to your desired tag(s) before importing your books. Don't forget to reset this after all books are imported.