For callouts with an explicitly set drop value, this property returns the vertical distance (in points) from the edge of the text bounding box to the place where the callout line attaches to the text box. This distance is measured from the top of the text box unless the AutoAttach property is set to True and the text box is to the left of the origin of the callout line (the place that the callout points to), in which case the drop distance is measured from the bottom of the text box. Read-only Single.
Remarks
Use the CustomDrop method to set the value of this property.
The value of this property accurately reflects the position of the callout line attachment to the text box only if the callout has an explicitly set drop value — that is, if the value of the DropType property is msoCalloutDropCustom. Use the statement PresetDrop msoCalloutCustomDrop to set the DropType property to msoCalloutDropCustom.