You can solve this if you want to use an applescript.
Just simply go to http://dougscripts.com/itunes/scripts/download.php?sc=explaylistastext and download the script.
Run it with Applescript Editor or Runner.
Then it will copy the playlist you want to the Clipboard. Go to text edit and just hit control v and paste it in there.
I know it is a work-around, but that is in case you are still trying to accomplish this.