How can I make (customize?) biblioentry references?

Now using current xsl stylesheets we can only make the single xrefs to
biblioentries, just like [text],[text],[text] or [1],[2],[3].
How can one (if it possible at all) make references grouped together,
for example [text,text,text] or [1,2,3] or even [1-3]?

Thank in advance,
Dimitry Ketov.