I'm trying to create a trendline in C#. I've found an example in VBA -- trying to modify without any luck. Having trouble with the trendline.Add statement (.Add) doesn't exist!

ActiveChart = (Excel._Chart)oWB.Charts.Add( Missing.Value, Missing.Value,
Missing.Value, Missing.Value );

ActiveChart.ChartType = Excel.XlChartType.xlColumnClustered;

ActiveChartSetSourceData(oWS.get_Range ("B2", "N5"), Excel.XlRowCol.xlRows);

ActiveChart.SeriesCollection(1).Trendlines.Add(....) // no Add here!

Thanks for your help!