A physicist shared with me his Astrophysics software to run on Mathematica Notebook. It consists of a page of statements of constants and initialization of variables, followed by another page of calculations in a large for loop. The calculations use the NDSolve() function and the FindRoot() function. Without typing in several pages of this highly compact code, is there a way to import it into Mathematica and then run the software ? When I open the notebook file using File-Open, I get a 3-page listing of the code and the result, but what I would really like to do is to change the inputs and run the software in Mathematica and create new output. I would be grateful for any advice you could provide - thank you.