Enqueing in Winamp with mod_mp3

hello everybody,

I am currently working on a php based interface for mod_mp3.  I should
have a demo site up soon to show everyone.  I am excited about it.  It's
coming along nicely.  I have a quick question for everyone though.  In my 
interface, users are able to make a playlist and then play that playlist. 
Everything works fine, i'm using the mysql dispatch, although any version 
above .35 would not work for some reason.  So when the user plays the
playlist, the links are sent to Winamp after sending a header of
audio/mpegurl.  My question is:  Is there a way to add more songs to the
current winamp playlist without overwriting the current playlist?  What
is happening now is is that if a user makes a new playlist and plays that 
it overwrites the one in winamp.  I would like the user to be able to
enqueue more songs to that playlist already playing in winamp, if
possible.  Also, what type of header is best to use for the mp3 player?
audio/mpegurl, audio/x-mpegurl?

Keep up the good work.  The mod is fantastic.
Thanks

Jon Buda
Kalamazoo, MI