Do I understand correctly that VSTO requires a full Setup.EXE
(or WEB server) in order to deliver a VB modified Excel File?

The problem is what we are doing with the data - GRAPHICALLY. I
have taken the database info that was gathered via Forms and created a
worksheet where each cell represents a 1" Grid to scale (50' x 16').
AutoShapes, polylines and connector OLEObjects are then placed on the
sheet. So far so good....

Where the ceiling comes in sight is allowing the objects to be
moved (and tracked to scale), dragging with attached connectors, editing
of the database criteria and enforcing business rules on that criteria
via events when an Object is edited.

What started as a text based Configurator has evolved into a
vector graphic application.