selecting into an included stylesheet

Hello,

Does anyone here know if it is possible to select into an
included/imported stylesheet from within a transform using Microsoft's
XSL implementation?

An empty document function can be used to select within the current
stylesheet, but this method does not work with included stylesheets.

I'm researching this as a possible alternative to using the document
function for referencing a common XML library. I have some evidence that
suggests that Microsoft's implementation of the document function caches
its requests differently (less persistently) than IE6 caches
stylesheets.

Thanks,
Utah Ingersoll