Rhino doesn’t have any tools to automatically add details to a mesh in places where the mesh doesn’t have detail. This is not just a question of changing some parameters. (going the other way - from the left shape to something like the right (disregarding the part that sticks up) - is simpler).
I am guessing but it would appear that you want to get a smooth NURBS object out of a rough mesh model. That process is called reverse engineering and is a very difficult process. There are a few plug-ins available to help you (check the resources page) but they tend to be expensive. There is also an informative document available on the Rhino wiki. Reverse Engineering [McNeel Wiki]
Success at Reverse Engineering, ie going from a mesh to smooth NURBS surfaces, is much more likely if the user knows how to create geometry starting from “scratch” with similar shapes and arrangement.