The m/ is unnecessary: it's used when you wish to change the / / to some other character. For example, m/irc/iS might become m&rc&iS. Also, you need to remove the :*: in the matchtext position if you're going to supply a regex matchtext. Here's how I would do your version:
on $*:TEXT:/w(h(a|o)|u)t is (yo)?u?r name\?/iS:#: msg # foo
