breaking an edge

Hi, I would like to break an edge in a model so that the resulting model has an added vertex at the specified location. In essence, I have the following work flow in mind: given compound -> get edge from two points -> break the edge at a specified location -> resulting compound has the edge broken at the point with an added vertex. From the geompy documentation, I see the method call MakeVertexOnCurve(), but that does not do anything to the original curve, or the compound. I would appreciate any advice regarding the same. Thanks, Manav