You do not need to use a "transform.php" page.
Instead make your rewrite be RewriteRule .*/teste/link/produto/evento.php?event=$1 [L]
In your "evento" page, use the code you had in your transform to egt the event ID. Then use this ID to display whatever you need:
$event = $_REQUEST['event'];
$select_evento = mysql_query("SELECT * FROM evento WHERE alias = '$event'") or die(mysql_error());
$evento = mysql_fetch_array($select_evento);
$count_evento = mysql_num_rows($select_evento);
$event_id = $evento['id'];
The basic idea is, don't redirect the user. Simply use the ID in the final PHP page.
On a side note, please consider using PDO for your MySQL queries. (lookup "mysql injection").