Update Answer from okx dot oliver dot koenig at gmail dot com for PHP 5.6 since e/ modifier is depreciated

// This finally helped me to do the job, thanks to Blackbit, had to modify deprecated ereg:
// original comment: "Squirrelmail contains a nice function in the sources to convert unicode to entities:"

function charset_decode_utf_8($string)
    {
        /* Only do the slow convert if there are 8-bit characters */
        if ( !preg_match("/[\200-\237]/", $string) && !preg_match("/[\241-\377]/", $string) )
               return $string;

        // decode three byte unicode characters
          $string = preg_replace_callback("/([\340-\357])([\200-\277])([\200-\277])/",
                    create_function ('$matches', 'return \'&#\'.((ord($matches[1])-224)*4096+(ord($matches[2])-128)*64+(ord($matches[3])-128)).\';\';'),
                    $string);

        // decode two byte unicode characters
          $string = preg_replace_callback("/([\300-\337])([\200-\277])/",
                    create_function ('$matches', 'return \'&#\'.((ord($matches[1])-192)*64+(ord($matches[2])-128)).\';\';'),
                    $string);

        return $string;
    }

Enjoy