Delphi Controlling Excel - Creating Pivot Tables and Charts - excel

Question

Delphi 10 / Seattle, with Excel 2013. I am writing a plugin (using AddIn Express) for Excel. One of the things that I need to do is create a series of Excel Pivot Tables/Pivot Charts. I have recorded macros within Excel, so I have VBA code to do what I want. My challenge is porting it to Delphi.
My code compiles, and when I step through it, the very last line gives me the error .. Method 'SetSourceData' not supported by Automation Object. FYI - XLApp is a variable point to the Excel Application.
procedure TMyTemplateForm.Pivot_TouchesByQuarter;
var
myPivotCache: OleVariant;
myActive_WB : OleVariant;
MyChart : OleVariant;
ChartSourceRange : OleVariant;
TabDestination : string;
begin
// Add the new Sheet
XLApp.Connect;
myActive_WB := XLApp.ActiveWorkbook;
XLApp.Worksheets.Add(EmptyParam, EmptyParam,1, xlWorksheet, LOCALE_USER_DEFAULT );
// Get a handle to the new sheet and set the Sheet Name
sheet_graph1 := XLApp.ActiveSheet;
sheet_graph1.Name := 'Graph1'; // CANNOT CONTAIN SPACES.. ?????
// Parameters: SourceType, SourceData, Version
// Doc at: https://msdn.microsoft.com/en-us/library/office/ff839430.aspx
myPivotCache := myActive_WB.PivotCaches.Create(xlDatabase,'Raw Data!R1C1:R1048576C36',xlPivotTableVersion15);
// Parameters: TableDestination, TableName, DefaultVersion
TabDestination := 'Graph1!R3C1';
myPivotCache.CreatePivotTable(TabDestination, 'PivotTable1',xlPivotTableVersion15);
// Select where we want this placed...
sheet_Graph1.Cells.Item[3, 1].Select;
// https://msdn.microsoft.com/en-us/library/office/jj228277.aspx
// Create the chart object
myChart := sheet_Graph1.Shapes.AddChart2(201, xlColumnClustered);
// Define the Range that is the source for the chart. This is the Pivot Table I created just above
ChartSourceRange := sheet_Graph1.Range['Graph1!$A$3:$C$20'];
// Tell the Pivot Chart to use the Chart Range
myChart.SetSourceData(ChartSourceRange);
end;
Why am I getting this error? As a related question, can I point my Chart Source to the PivotTable1 object? Right now, it is hard coded to specific cell locations, but depending on the data, my Pivot table can be bigger than from Row3 to Row20.
If it helps any, the VBA macro code (last 2 lines) is..
ActiveSheet.Shapes.AddChart2(201, xlColumnClustered).Select
ActiveChart.SetSourceData Source:=Range("Sheet1!$A$3:$C$20")

Answer 1

I found the answer. Instead of
// Tell the Pivot Chart to use the Chart Range
myChart.SetSourceData(ChartSourceRange)
the code should be
myChart.chart.SetSourceData(ChartSourceRange);