Hi…
We need to apply custom chart type to a Chart control programmatically using Chart.ApplyCustomType Method.
Here is the sample from msdn ..
private void Create3DPieChart()
{
this.Range["A1", "A5"].Value2 = 22;
this.Range["B1", "B5"].Value2 = 55;
Microsoft.Office.Tools.Excel.Chart chart1 =
this.Controls.AddChart(this.Range["D2", "H12"],”chart1");
chart1.SetSourceData(this.Range["A1", "B5"],Excel.XlRowCol.xlColumns);
chart1.ChartType = Excel.XlChartType.xl3DColumn;
chart1.ApplyCustomType(Excel.XlChartType.xl3DPie,missing);
}