maz, I agree about the bold and underlined letters. Most French/Spanish letters and umlauts also worked in preview. But that's as far as it went. If that was the extent of your non-English characters, it might have seemed to you that everything showed up the way it did in preview. Any other characters would not work in preview. That includes c with a cedilla, a dotless i, anything Asian, and so on.
Basically, if you go to the Wandel site and put in a bunch of text, the things that got translated into codes would not show up. The things that were translated as themselves (ü=ü, no codes needed) would show up.
