Thanks to stackoverflow and other resources I've been able to manage having a column chart drilldown to a spline chart, as long as the spline chart only has one set of data.
I now would like the column chart to drilldown to a spline with series data so that the spline chart will show several lines, but I can't seem to get this to work.
Here's the JSFiddle: http://jsfiddle.net/phdjsep/qjQPm/3/
If you can figure this out, could you please provide a brief explanation? I've been beating my head on the desk for days.
Thanks in advance!