codice:
<?php
$stringa = "Testo da modificare";
$caratteri_speciali = array( '!','"','#','$','%','&',''','(',')','@','€','à','á','â','ã','ä','å','æ','ç','è','é','ê','ë','ì','í','î','ñ','ò','ó','ô','õ','ö','ø','ù','ú','û','ü','ý','ÿ' );
$caratteri_sostitutivi = array('%21','%22','%23','%24','%25','%26','%27','%28','%29','%40','%20AC','%E0','%E1','%E2','%E3','%E4','%E5','%E6','%E7','%E8','%E9','%EA','%EB','%EC','%ED','%EE','%F1','%F2','%F3','%F4','%F5','%F6','%F8',%F9',%FA',%FB',%FC',%FD','%FF');
$stringa = str_replace($caratteri_speciali,$caratteri_sostitutivi,$stringa);
echo "modificata = $stringa";
?>
Vedi se ti può servire per filtrare i dati che prendi dall'xml...