Saving Playlists

I'm not sure what you're asking.

You can right-click a playlist and choose Export Song List into an XML file.

But there's no way to "lock" a playlist.

Can I replicate all my iTunes playlists and songs (JUST the way it is on my current mac) on a new mac? My iTunes folder is on an external drive. I'm worried that I will have to drag and drop each song to replicate my old playlists...