Your question is very vague... but I can tell you this:
There is a GLOBAL MODEL and a SUBMODEL. I suppose that you are asking if you can use a different step on the SUBMODEL. It is a posibility if you have the specific purpose. You can make a dynamic step in your GLOBAL MODEL and for some specific region make a SUBMODEL with a static step. Is up to you verify that the SUBMODELING assumtions are correct.
If you want to reproduce the same conditions you must use identical steps, loads, BC,etc in both GLOBAL MODEL and SUBMODEL.
You can read about this in the manual.