Some xml documents I want to process have an element report with attribute input containing the path to another file, like this:
<report timestamp='Mon Dec 08 16:15:35 GMT 2003' input='c:\work\december\test.xml'>

In my XSLT script, I want to create a global variable that contains an altered version of the name of this external file -- so 'test.xml' should become 'test-marked.html'

How can I do this with XSLT -- either 1.0 or 2.0?
[I use Saxon to process my XSLT scripts]