Advanced Cut tool

Hello everybody,

       I'm new to this wonder world, I have some issues regarding default cut tool provided with 3ds max, its not giving smooth corner curves to the modle(exp: rounded arc rectangle). 

      Actually I'm trying extend some new look to my modle i.e deep windows , previously I was managed the same with by using alpha channel.

    My requirement  Is there any plugin or script which is capable of selection of poly by material color range (in this case only windows color, for example black) then cut the poly by selecting color range.

Simply If a rectangle plane has max 2 polygons and want to cut some smooth shape in the middle of rectangle, creating the required shape on material(with black or some x color) , apply mat to  rectangle and select the color range from poly( black or some x color) then cutting poly with the color range.

Thanks in advance