risolto, per i posteri...


$_SERVER['PHP_AUTH_USER'] = "user";
$_SERVER['PHP_AUTH_PW'] = "password";


$page_book = "www.miosito.com/miapagina.html";

$fp1 = fopen("http://{$_SERVER['PHP_AUTH_USER']}:{$_SERVER['PHP_AUTH_PW']}@$page_book", "r");

while(!feof($fp1)) echo fgets($fp1, 4096);

fclose($fp1);