Thanks all for your comments. I think I can simplify my inquiry:

I need to be able to import an XML file specified in my source document and
process it using templates in my ORIGINAL xsl file. I suspect that the
document() function allows me to do exactly this, but I am very unclear on
the mechanics. Any thoughts on this simplified problem?

 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list