This association between WingDings and sinister messages is hardly new - various hoaxes have been suggested for well over a decade now.
The specific reference to a plane crashing into a tower having the flight number Q33 NY is basically a lie. The planes in question were American Airlines Flight 77 and the second was United Airlines Flight 175. And no, Q33 NY was not the unique plane number either - All such numbers in the US start with an N,
This site below is similar to Snopes, and on this occasion has much more detail, particularly in the data table at the bottom.
http://www.hoax-slayer.com/wingdings-911.html