query_posts, sort post by cat_id

The problem is that it is necessary to with draw the posts of certain categories which are subcategories.
Posts must be sorted to these subcategories, either by ID, or set manually.

query_posts(‘cat=2&orderby=title&order=asc’);
Category whith ID=2 have a subcategories. Need sort by them.

If code is:
query_posts(‘cat=4,5,6,7,8’); //by ids subcat
All the same, sorting is conducted by the parent category 2.

And I need sort post by their subcategories 4,5,6,7,8.

How should complement the request?