Shape.CalloutTarget Property (Visio)
Gets or sets the target shape that is associated with the callout shape by a callout relationship. Read/write.
expression A variable that represents a Shape object.
If you attempt to get or set the CalloutTarget property value on a shape that is not a callout, Microsoft Visio will return an Inappropriate Source Object error.
If no target shape is associated with the callout shape, the CalloutTarget property returns Nothing. Setting the property value to Nothing removes any target shapes that are associated with the callout shape.