Generate chart in Excel - C #

Hello, I would like to ask a question: I am exporting the generated data in a gridview to Excel, and at the same time I am generating a Graph in Excel itself from C #. I would like the chart size to increase dynamically according to the size of the range. It is currently set statically.

Chart Generation Code:

           

        Microsoft.Office.Interop.Excel.ChartObjects xlCharts = (Microsoft.Office.Interop.Excel.ChartObjects)xlWorkSheet.ChartObjects(Type.Missing);


 /  DEFINE GRAPH SIZE  / Microsoft.Office.Interop.Excel.ChartObject myChart = (Microsoft.Office.Interop.Excel.ChartObject) xlCharts.Add (20, 160, 600, 500) ;
            Microsoft.Office.Interop.Excel.Chart chartPage = myChart.Chart; 

 /  RANGE FOR GENERATING THE GRAPHIC  / CR = xlWorkSheet.get_Range ("C: C", "D: D");
            chartPage.SetSourceData (CR, misValue);
            chartPage.ChartType = Microsoft.Office.Interop.Excel.XlChartType.xlColumnClustered; 

    }
 

Could you please help me?