Chart.BarShape (PowerPoint)
Returns or sets the shape used for every 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.BarShape = xlBox