DropLines Object (PowerPoint)
Represents the drop lines in a chart group.
Drop lines connect the points in the chart with the x-axis. Only line and area chart groups can have drop lines. This object is not a collection. There is no object that represents a single drop line; you either enable drop lines for all points in a chart group or you disable them.
If the HasDropLines property is False, most properties of the DropLines object are disabled.
Although the following code applies to Microsoft Word, you can readily modify it to apply to PowerPoint.
Use the DropLines property to return the DropLines object. The following example enables drop lines for chart group one of the first chart in the active document and then sets the drop line color to red.