use encoding 'utf8';
use HTML::Entities 'decode_entities';

my $string = 'Hello ä/ä ... ß,é';

$string =~ s/(.)/ord($1)>160?'&#'.ord($1).';':$1/ge;

print "$string\n";                     # encoded
print decode_entities($string),"\n";   # decoded

##</code><code>##

use encoding 'utf8';
print '&#' . ord('ä') . ';';   # prints &#228;