Show sticky posts, or specific posts, above randomised posts on front page

I am randomising post order using <?php query_posts($query_string . ‘&orderby=rand’) ?>

However this seems to override the sticky post function.

So what I need is the php code to either specify that sticky posts are shown before the randomised posts, OR that specific post ids need to be shown before randomised posts. All on the front page of wordpress blog.

Many thanks for any help.