Here for someone's benefit is a working example of creating an Excel chart on a worksheet:

     private void buildGraph()

    {

        try {

            worksheet.getOleMessageLoop().doInvokeAndWait(new Runnable()

            {

                public void run()

                {

                    createChart(worksheet);

                }

            });

        } catch (InterruptedException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        } catch (InvocationTargetException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }

    }

    public static void createChart(Worksheet worksheet)

    {

         _Worksheet ws = worksheet.getPeer();

         IUnknown disp = ws.chartObjects(Variant.createUnspecifiedParameter(),new Int32(0));

         ChartObjects objects = new ChartObjectsImpl(disp);

         DoubleFloat left = new DoubleFloat(500);

         DoubleFloat top = new DoubleFloat(100);

         DoubleFloat width = new DoubleFloat(300);

         DoubleFloat height = new DoubleFloat(300);

         ChartObject chartObject = objects.add(left, top,width, height);

         chartObject.setName(new BStr("normalDistChart"));

         _Chart chart = chartObject.getChart();

       com.jniwrapper.win32.excel.Range valuesRange = ws.getRange(new Variant("distributionRange"),Variant.createUnspecifiedParameter() );

       chart.setSourceData(valuesRange, new Variant(2));

       chart.setChartType(new XlChartType(4));

       chart.setHasLegend(new Int32(0), new VariantBool(true));

       chart.getLegend(new Int32(0)).setPosition(new XlLegendPosition(XlLegendPosition.xlLegendPositionBottom));

       chart.setHasTitle(new Int32(0), new VariantBool(true));

       chart.getChartTitle(new Int32(0)).setText(new BStr("Normal Distribution Demo"));

      Series series = new SeriesImpl(chart.seriesCollection(new Variant(1), new Int32(0)));

      series.setName(new BStr("Cumulative"));

      series = new SeriesImpl(chart.seriesCollection(new Variant(2), new Int32(0)));

      series.setName(new BStr("NonCumulative"));

    }

Thanks

Louis