Restore specific posts from database

I have had to setup my multisite wordpress blog from scratch after quite a serious injection of malicious code.I exported posts from most of the sites with wordpress export but unfortunately skipped a couple of them.

I only need to restore posts from a couple of blogs e.g wp_8_posts

I have a test site which I erased completely and have uploaded the backup database of my live site

How (if possible) can I introduce these into the test site database in order to then view them as posts in the test site?

Thanks in advance
Mark M.