c:\@Work\Perl\monks>perl -wMstrict -le
"my $word = '$-.%aBc&/';
 my $new_word =
   join '',
   map { /[[:alpha:]]/ ? qq{[$_]} : $_ }
   split '',
   $word
   ;
 print qq{'$word' -> '$new_word'};
"
'$-.%aBc&/' -> '$-.%[a][B][c]&/'