Series.XValues (PowerPoint)

Returns or sets an array of x values for a chart series.

You can set the XValues property to a range on a worksheet or to an array of values, but not to a combination of both. For PivotChart reports, this property is read-only.

ActivePresentation.Slides(1).Shapes(1).Chart.FullSeriesCollection(1).XValues = "=Sheet1!B2:B5"