It does work for MOHaa on my computer.
So it can work on yours.

doesn't work on mine either. the special signs aren't replaced with ???'s, they're replaced by .........
it's wierd.

All of the alt codes works well in chatscreen.
Part of them is represented by a ? in the score.

Examples that work fine for me in both chat and score:
(I think approximately half of the total list on the linked website)
€
™
©
®
±
¼
½
¾
alt-0192 until alt-255