Poose et al.,
Once you know a character code (from looking it up once in a table), there is another simple way of entering it:
* Hold down the [Alt] key and type in the code (4 figures, so add a zero if your table has 3 figures) on the numeric keypad.
Simple and useful if you use only a few codes regularly; I use it for Ç (capital ç), Alt 0199 and ß (German sz, or beta), Alt 0223.
The √ code unfortunately is font/keyboard specific, so can't help you there....
CJ