use-when in the xsl:inlcude

Hell,

Is there something I can pass to xslt for it to evaluate that something 
in the use-when attribute in the xsl:inlcude, and xsl:import?

In particular I'm using saxon in java.

P.S. I almost certain that the answer is no, but who knows.

P.P.S. The only way I have found is though an extension function, 
unfortunately stateless, thus useless, unless I use thread statics.

Thanks.
--
Vladimir Nesterovsky
http://www.nesterovsky-bros.com