Sure. It actually work for me pretty good now, as long the list is modified. The steps are:
1. Save WMP playlist to m3u extension. It is a option that supported by window media player and Linkstation treats it as playlist. .asx extension is too complicate to be modified. The playlist should be placed on your designated PC_CAST folder or suborders. Linkstation will find it automatically.
2. Use any text editor to edit your m3u playlist. You need to change all absolute path to relative path. For example: \\LinkstationXXX\music_folder\your_music to the format like music_folder\your_music. Path name varies depend on where you place your music playlist. If necessary, use [..] to go up on the folder tree. use [..\..] will move the folder pointer to two level above your playlist folder. It can be automatically replaced using any text editor in a couple seconds,
3. Since m3u is microsoft format, it has to be Buffalo's fault. WMP write out m3u folder tree using [\], yet the Linkstation read folder tree ladder using [/]. A bug on Buffalo's side for sure. So open the text editor again, and replace all [\] to [/]. It will take another couple seconds.
4. Now save the edited list and update PC-CAST list. The playlist will now be served by Linkstation live and playable by any DLNA network player. In my case, it is the YAMAHA A/V receiver.
By the way, my Linkstation live firmware is 1.02 and it works very good. No idea it will work for other f/m version. My playlist is currently has 185 songs and 14+ hours music content.
Enjoy!