Yes, it sure is, but when the ASCII code was defined they placed it in a mid-position where it could not be used as an accent. Today, things are different, there are foreign language character sets for just about every language in the world.

In MS Word you can press control and an accent character then press the letter and Word will insert the appropriate character. So if you press "CTRL ~" and then press "a", you get a Spanish nasal "a". The other characters that can be used in this way are ":" for umlaut, "^" for circumflex, "," for cedilla, "/" for slash-through (Scaninavian O), apostrophe for accute accent, and Baza's apostrophe for grave accent.