As @AlanG has said, his script handles that. There’s also the Various Complements and the People Link plugins in the community plugins that do something similar. Personally I’ve ended up settling on the People Link plugin to handle the @ lookup (it pops a lookup on a specific folder that has all my contacts/people in it), and also the Supercharged Links plugin to mark any links to files in that folder with an emoji:
Just my preference to not have the extra character directly in the filename.