Hi Dennis
maybe this exerpt from the MSDN Site might help?
==========
Mouse Events for Shapes
Visio mouse events are exposed on Page and Window objects. To locate a
particular shape in a page or window on which a user clicks, developers must
use the Visio SpatialSearch method. The following C# code passes in the x-
and y- coordinates for the click event on the window, sets Visio constants
that dictate how to set up the selection object, and defines a small
tolerance in which to search around the x- and y- coordinates.
MySelection = Window.SpatialSearch(x, y, visSpatialContainedIn,
0.001, visSpatialFrontToBack)
If the tolerance is set to a very small unit relative to the size of the
shape, the selection object returned by the SpatialSearch method will only
contain one shape, the one that the end user clicked on in the window.
=================
from:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/odc_vis2003
_ta/html/odc_VSProgrammingwithVisioActiveXControl.asp
Regards
Matt