are meta playlists possible?

[mkh]

my playlist is 50 tracks, 30 of which are from 2 separate mixtapes (15 tracks each).

I want to randomize the entire playlist, designate 2 meta-playlist sections such that Winamp will treat both of the 15 track mixtape sections as their own playlist that should not be randomized. That way the mixtape tracks are played in correct order, and everything else can remain randomized.

Is this currently possible?

Thanks all