I copy my playlists to my usb drive with windows media player. The format of the .wpl file has a few lines of meta data within the <head></head> lines which are not necessary but what is needed to play your songs is in the lines after:
<?wpl version="1.0"?>
<smil>
<head>
<meta name="Generator" content="Microsoft Windows Media Player -- 12.0.7601.17514"/>
<meta name="ItemCount" content="3"/>
<meta name="IsFavorite"/>
<meta name="ContentPartnerListID"/>
<meta name="ContentPartnerNameType"/>
<meta name="ContentPartnerName"/>
<meta name="Subtitle"/>
<author/>
<title>My Favorites</title>
</head>
<body>
<seq>
<media src="..\30 Seconds to Mars\This Is War\Closer To The Edge.mp3"/>
<media src="..\Adele\21\Rolling In The Deep (Album Version).mp3"/>
<media src="..\Adele\21\Turning Tables.mp3"/>
</seq>
</body>
</smil>