Showing posts in categories

Hello,

I have altered my homepage to only show posts from category “13”. But I would also like to add an extra category to posts, so I can show them in other archives too. The way it’s set up now, it doesn’t allow this. How could I assign a post two categories and still display only category 13 on the homepage and in the archive of the other category.

Used categories are 6-4-11-1.

<?php
	                              $paged = (get_query_var('paged')) ? get_query_var('paged') : 1;
        	                      $args = array(
                	              'cat' => 13, // category ID you want to exclude
                        	      'posts_per_page' => 5,
	                              'paged' => $paged);
	                               query_posts($args);
        	                ?>