CALLOUTTARGETREF Function
Returns a sheet reference to the target shape of the callout shape.
Version Added: Visio 2010
CALLOUTTARGETREF()!
ShapeSheet reference
If the shape is not a callout shape, or if it is not associated with a target shape, CALLOUTTARGETREF returns #REF.
CALLOUTTARGETREF()!Height
Returns the value in the Height cell of the shape that is associated with the callout.