Modify WordPress loop after it has been run

First:

• Indent your code consistently, your code editor should do this automatically, if it doesn’t, you should change, I can recommend Sublime Text as a free option, but there are hundreds of others
• Don’t spam PHP tags, <?php echo 'you'; ?><?php echo ' dont '; ?><?php echo 'need ';?><?php echo 'this'; ?>, when <?php echo 'you can just open tags once and close them when your done?';?>
• Never use query_posts. If I was your employer I would have fired you for such a thing. Whoever taught you to use it, they did you a disservice. To fetch posts in WordPress, use WP_Query or get_posts, to modify a query, use the pre_get_posts filter. Remember to call wp_reset_postdata afterwards to clean up
• Pick a style and stick to it, you either if() {} or if(): endif;, don’t mix the 2 types, it just makes life difficult and your code difficult to read

As for your issue, just print out 9 posts. Wrap the 9th post in a div that’s hidden by default and toggle it’s visibility with javascript when you press a button.