Hello Jens,
I do not understand how you would like to use XSD as a template for your XML. You can certainly create XML output instead of, for instance, HTML. If you compose the report output correctly, it can certainly be made to satisfy a schema definition.
The easiest way to do this would likely be to start with an HTML recipe in your server's /data/reports/recipes directory. Copy the recipe, and modify it to form the XML you are looking for.
Regards,
Kael