Custom Post Type Query

I am modifying a theme that query’s post categories that you choose from the wordpress dashboard. I have added a custom post type and I want to pull in a specific category from the custom post type instead. I would like to hard-code this category into the theme file (instead of making it editable from the wordpress dashboard as it is now). I just need to figure out the query for the custom post type. post types are named “Listings” and I want to be able to pull in 6 posts from a category within the custom post type with the either the slug or category id.

Here is my modified functions code that created the custom post types:

/** Listings */
add_action('init', 'listing_register');

function listing_register() {

	$labels = array(
		'name' => _x('Listings', 'post type general name'),
		'singular_name' => _x('listing Item', 'post type singular name'),
		'add_new' => _x('Add New', 'listing item'),
		'add_new_item' => __('Add New listing Item'),
		'edit_item' => __('Edit listing Item'),
		'new_item' => __('New listing Item'),
		'view_item' => __('View listing Item'),
		'search_items' => __('Search listing'),
		'not_found' =>  __('Nothing found'),
		'not_found_in_trash' => __('Nothing found in Trash'),
		'parent_item_colon' => ''
	);

	$args = array(
		'labels' => $labels,
		'public' => true,
		'publicly_queryable' => true,
		'show_ui' => true,
		'query_var' => true,
		'menu_icon' => get_stylesheet_directory_uri() . '/article16.png',
		'rewrite' => true,
		'capability_type' => 'post',
		'hierarchical' => false,
		'menu_position' => null,
		'supports' => array('title','editor','thumbnail')
	  ); 

	register_post_type( 'listing' , $args );
}

register_taxonomy("listing_category", array("listing"), array("hierarchical" => true, "label" => "Categories", "singular_label" => "Category", "rewrite" => true));

Here is the code from the theme file that currently pulls in categories from a regular post:

<?php
			$cc = 0;
			$c = 10;

			$posts_num = option::get('featured_categories_posts');

			while ($cc < $c)
			{

				$cc++;
				$category = option::get('featured_category_'.$cc);

				if ($category != 0)
				{

					$cat = get_category($$category,false);
					$catlink = get_category_link($$category);

					$loop = new WP_Query( array( 'post__not_in' => get_option( 'sticky_posts' ), 'posts_per_page' => $posts_num, 'orderby' => 'date', 'order' => 'DESC', 'cat' => $category ) );
					?>

					<div id="tab1" class="tab_content">
					<?php if ( $loop->have_posts() ) : ?>
					<ul class="posts">
						<?php
						$x = 0;
						while ($loop->have_posts()) : $loop->the_post(); update_post_caches($posts); $x++;
						?>
						<li<?php if ($x == 6) {echo ' class="last"';} ?>>

							<div class="cover">
								<a href="<?php the_permalink(); ?>" title="<?php the_title_attribute(); ?>"><img src="<?php echo $image; ?>" alt="<?php the_title_attribute(); ?>" /></a>
							</div>

							<h2><a href="<?php the_permalink(); ?>" title="<?php the_title_attribute(); ?>"><?php the_title(); ?></a></h2>

						</li><?php endwhile; ?>

					</ul><?php endif; ?>

					</div><!-- end .tab_content -->

				<?php } // if category is set
			} // endwhile ?>

Thanks in advance!