I don't know anything about LW.  But, if you really want them in there as named, export them individually from Poser as objects.  Just don't change their position.  Then, import them into LW, don't change their position but rename them to the appropriate group names.  Then, just lock them in place once they're all imported (however LW accomplishes that) so you can't move them and save the file as a default start file for creating cloth.  Unless your're rigging in LW as well (I wouldn't know) you don't need the skeleton for anything.   (I don't know sqaut about LW so none of the above may yield any help at all. :) )