La butto lā al volo...

codice:
$query = mysql_query('SELECT * FROM tabella');
while($temp = mysql_fetch_field($query)) {
    if($temp['name'] == 'campo_escluso') continue;
    $fields[] = $temp['name'];
}

$new_query = 'SELECT '.implode(", ", $fields).' FROM tabella';
Prova e fammi sapere.

Ciao