Exclude a category on this theme’s homepage

I am trying to exclude a specific category (category 23) from being displayed in an area of the homepage that is coded like this:

<?php
	if ($featured2_cat == '-5') {
		if (count($stickies) > 0)
			$query2 = array('post__in' => $stickies, 'showposts' => arras_get_option('featured_count') );
	} elseif ($featured2_cat == '0') {
		$query2 = 'showposts=' . arras_get_option('featured_count');
	} else {
		$query2 = 'showposts=' . arras_get_option('featured_count') . '&cat=' . $featured2_cat;
	}

	$q2 = new WP_Query($query2);
	arras_render_posts($q2, arras_get_option('featured_display'), 'featured');
	?>
</div><!-- #index-featured -->
<?php endif; ?>

I have tried what I could find in the Codex, but this seems to be a different way of displaying posts. Any suggestions what I would add to exclude category #23?

Thanks for any help.