By backing it up I hoped to be able to access the notes without unlocking it, and the notes aren't transferred to the computer with the sync. I also hoped to avoid syncing it because I recently had to replace the motherboard in my computer which caused me to loose a lot of data, including all the music I had on my iTunes from CDs, and I didn't want to loose them from my iPod, but I suppose it's worth a try because it's not working anyways, thanks.
If you can't do this
you are out of luck with regards to backing up to iTunes.
If you can enter the iPod then you can backup to iCloud but from your description you may not have access to the iPod.
I think that you ae out of luck because you rebuild the computer and the iPod sees it as a new computer. The security features of the iPod/iOS/iTunes are at work.