Yes. Go to your Subsonic playlists folder (/var/subsonic on Linux) and open up the m3u or pls file of the desired playlist in a text editor such as nano or gedit.
If you're on Windows, I'm not 100% sure where it stashes the playlists. Maybe C:\subsonic\playlists or C:\Program Files\Subsonic\playlists or something... and you'd want to edit the file with Notepad.
The point of this post, is that the path to the songs in your playlist is stored line-by-line in the playlist file.
-Kirk