Upgrade of HSSF to XSSF Excel serializer, anyone?

Hi Cocooners,

I have just run into the 65535 upper limit on the number of rows in an
Excel workbook as serialized using the gnumeric schema.

Of course, I tried substituting the latest poi-3.10 jar from the excellent
POI project for 3.0.2.jar that has worked well so far. Alas, some of the
methods no longer exist.

I was hoping somebody has done the hard-work necessary to upgrade the
serializer to the XSSF format. I would be very grateful if they could share
the code for 2.11

Thanks

Warrell