I think that the "right" answer is to just create a scheduled report (reusing the query from the portlet) in your reporting tool (Jaspersoft/BO) and distribute the output via email.
But if you really don't want to use a report-tool, then you could build (in "any" technology) something that called the portlet's existing query (via SOAP) and process the output (processing that response XML can get a bit technical though). I have built a number of things like that in Excel, but not anything that is scheduled as such I'm afraid (my Excel things rely on the use initiating the thing - open Excel, provide a parameter, press a button etc).
Ultimately it depends really what schedule options you have in your "infrastructure" as to what you would choose to handle the scheduling / report production / distribution etc (all those sort of problems are handled 'normally' by the report-tool of course).