Importing old posts from previous version back-up

Help. This is all new to me. I had a few posts before I upgraded to 2.6 and backed them up before hand. I had a problem and started from scratch again. I have new posts on the 2.6 version. I have also backed up these. Is there any way to get the original posts from my first back up and import them to the upgraded version without losing my new posts?
Thanks