oh, sorry, your suggestion wasn't unrealistic enough to not be believable so my sarcasm detector failed.

i took ___ to mean the option key which has this symbol made up of lines: "⌥", it is also the key most likely to be used for such a feature, so i figured that's what you must be talking about.

if you weren't then the key most certainly doesn't exist on a mac either, and i apologize for the downvote. unfortunately it appears that i can't undo it anymore so i hope someone else will compensate with an upvote.