Series.BarShape (PowerPoint)

Returns or sets the shape used for a single series in a 3D bar or column chart. Possible return values are xlBox - A box, xlConeToMax - A cone, truncated at the specified value, xlConeToPoint - A cone, coming to a point at the specified value, xlCylinder - A cylinder, xlPyramidToMax - A pyramid, truncated at the specified value, xlPyramidToPoint - A pyramid, coming to a point at the specified value.

ActivePresentation.Slides(1).Shapes(1).Chart.FullSeriesCollection(1).BarShape = xlBox