Have you tried
http://en.wikipedia.org/wiki/Mathematical_operators_and_symbols_in_Unicode[
^]
I cant understand what this has to take from html...
Whenever you will use math symbols mostly it will be in UNICODE format.
if you dont want to use UNICODE ,I believe you will obiviously have to shift to some image manipulated symbols.
Also it is suggested to copy the symbols from link provided and paste in Word.It'll work