The AutoPieChartTitle object controls the pie chart title settings and it is accessed from AutoPieChart object Title property.
The following script demonstrates how the AutoPieChartTitle object is used.
'Declares GrapherApp as an object
Dim GrapherApp As Object
'Creates an instance of the Grapher Application object
'and assigns it to the variable named "GrapherApp"
Set GrapherApp = CreateObject("Grapher.Application")
'Makes Grapher visible
GrapherApp.Visible = True
'Creates a plot document in Grapher and assigns
'it to the variable named "Plot"
Set Plot = GrapherApp.Documents.Add(grfPlotDoc)
'Declares PieChart as an object
Dim PieChart As Object
'Set the Pie chart to the PieChart object
Set PieChart= Plot.Shapes.AddPieChart("C:\Program Files\Golden Software\Grapher 13\Samples\pie.dat",1,2)
'Set the title for the pie chart to the PieChartTitle object
Set PieChartTitle = PieChart.title