Convert from numbers to letters

[Jason Drew]

Oh yeah, oops, thanks. (I mean the line continuations, not the alleged
sin against man and nature, an accusation which I can only assume is
motivated by jealousy :-) Or fear? They threw sticks at Frankenstein's
monster too. And he turned out alright.

My elegant "line" of code started out without the enclosing
parentheses; forgot I didn't need the \s when I embraced it.