You could make the invisible files on your iPod visible, and then just navigate through until you find the files (they have weird names like M40VP.mp3).
Open Terminal, and enter:
defaults write com.apple.finder AppleShowAllFiles TRUE (hit enter key)
killall Finder (hit enter key)
Then go to the iPod on your desktop and browse around until you find them. Then just copy them over. Once you're done, enter:
defaults write com.apple.finder AppleShowAllFiles FALSE (hit enter key)
killall Finder (hit enter key)
As long as you stick to my directions above, you'll be fine. If you don't feel comfortable with Terminal, then I guess wait for other people's advice. This is how I do it because it doesn't need a software program.