The same we do manually with window select, now available for scripting
command name: ecncSS
Base point: (x,y,z)
Square half value
coo = "1,1,1"
cmd = "ecncWS " + coo + " Enter Enter"
Rhino.Command cmd, True
Let say we have a point in X-Y space and want to select everything under
and above that point in Z direction, the ecncWindowSelect will help you
incorporate window select into your scripting code
ecncWindowSelect (ecncWS) RhinoV4