How to create MACRO in UG NX?

Hi, 

       I am totally new to Macro, & i have no idea how to create a MACRO.
1. I want to create a MACRO in which i can extract the surfaces of particular radius from a part. 
2. further i want to roll a sphere on that part & then i need surfaces of particular radius which will come in contact with sphere after rolling over that part.

kindly guide, how to proceed?