Verified answer

Open a Word document. Go to Insert > symbol. Pick up the symbol you want to use, check other fonts as well! Then you can copy & paste your symbols anywhere you want.

If you're referring to the box with the question mark, that means there's a unicode character/symbol that you can't see. You're welcome to copy and paste any unicode symbol to have it show up as a question mark, but some other people might see it as an actual character.

Unicode characters are how computers display Arabic, Greek, Cyrillic, and many more non-Latin alphabets. They also have really fun little symbols for science, math and the weather. You can check them out here: http://www.alanwood.net/unicode/miscellaneous_symb...

Edit: You can either copy and paste from that site I gave you, or check out the symbols here (there's instructions at the bottom): http://www.tedmontgomery.com/tutorial/ALTchrc.html

Looks pretty square to me....