If I understand what you want correctly: areaA=a category and areaB=another category, query_posts() should do it:
http://codex.wordpress.org/Template_Tags/query_posts
Two snags. The first that you would need a counter, which only ticked up when the category matched the one you were looking for, but that is easily adapted from one of the previous posts, if not explained on the page I linked to. The second is that you would need multiple loops, as explained here:
http://codex.wordpress.org/The_Loop