Questions about $wpdb->prepare()

1:
Is there a placeholder for a columname so we can have something like:
$wpdb->prepare("SELECT * FROM $wpdb->tablename WHERE columname = %s ORDER BY %??", $value, $sortby)
If not, please make it an enhancement request

2:
Is there a placeholder for an enumeration of integer values so we can have something like:
$wpdb->prepare("SELECT * FROM $wpdb->tablename WHERE id IN (%??)", implode(',', $intvaluearray))
If not, please make it an enhancement request