[Plugin: NextGEN Gallery] Nextgen Search Refining?

I have a search set up and working with Nextgen Gallery, but I need it to search specific galleries rather than all of them. How would this be achieved? My code is the usual modification, as listed below…

function ngg_get_search_pictures ($keywords, $numberPicRow = NULL) {
	global $wpdb;
	$count=1;
	if (!$numberPicRow) { $numberPicRow = "4"; }

	$nngquery = "
SELECT pid,description,alttext
FROM   wp_ngg_pictures
WHERE  MATCH (description, filename, alttext) AGAINST ('*$keywords*' IN BOOLEAN MODE)
AND exclude = '0'
UNION
SELECT pid,description,alttext
FROM wp_ngg_pictures, wp_terms, wp_term_relationships
WHERE pid = object_id and term_id = term_taxonomy_id and
MATCH (name) AGAINST ('*$keywords*' IN BOOLEAN MODE)
AND exclude = '0'
				";
	$pictures = $wpdb->get_results($nngquery, ARRAY_A);

	if ($pictures) foreach($pictures as $pic) { 

		$out .= '<a href="'.nggGallery::get_image_url($pic[pid]).'" title="'.stripslashes($pic[description]).'" rel="gallery'.$pic[pid].'">';
		$out .=  '<img class="ngg-gallery" style="border: .1em solid #FFFFFF" src="'.nggGallery::get_thumbnail_url($pic[pid]).'" alt="'.stripslashes($pic[alttext]).'" title="'.stripslashes($pic[alttext]).'" />';
		$out .=  "</a>\n";
				if ($count == 0) {
				$out .= "";
				}
				++$count;
				$count%=$numberPicRow;
	}
	return $out;
};