I tried your lisp but Im not getting the center of the object I'm getting output (66594.1 1.678e+006) which is out of the bound. Please refer to the drawing I have attached to this reply.
My main motive is to shift the center of the bound box to 0,0 position. Like datum feature in NX cam.
I googled a bit and Geometric center can help me but I'm using AutoCAD 2012 and the feature is added in 2016
PS: I have tried this on AutoCAD and not IntelliCAD