Analyzing circuit scheme (how element are connected)

[ivan]

I got a scheme like the one attached. It can contain up to 30-40 elements.
i'm generating derivative  schemes by excluding some part of this diagram (it's colored blue and set to be non-printable). shape's parameters (sequence shape numbers etc) then recalculated  to match new topology. it's done automatically atm.
I need to simplify any derivative  schemes to the simpliest form. with one resistance (box) and one source (circle). and i need as much detailed transformation as possible
Rules to simplify are rather simple - i have to search and process serial and parallel connections (see second image as a guide).
atm i partly automate it  - i select shapes (serial or parallel one ) by hand and run a macros. Macros then writes all calculations needed nto doc file and replace several initial shapes with result ones.
But i want to automate this "selection". I need a macros that will find serial/paralle conection on my scheme. How can i do it ?

[ivan]

visio file with a scheme (note that blue elements can be  deleted)