A few things. First of all, I want to double-check that the file you're talking about is indeed an .m file. .m files are MATLAB scripts/functions, i.e., files which contain instructions telling MATLAB to do things. .mat files, meanwhile, are files used to store MATLAB data.
If indeed it's the case that you're storing data/parameters in an .m file, then step 1 is to save that information properly to a .mat file, and step 2 is to never store data/parameters in an .m file ever again. To do step 1, load up all that info into MATLAB variables in your workspace, and then use the save command to save it to a .mat file. From then on, you just need to use the load command to load up that data in MATLAB. Step 2, meanwhile, is self-explanatory.
Now, assuming you've got your data in a .mat file, to convert to an Excel file, you'll want to read up on xlswrite.
Finally, if you literally want the text in an .m file to be copied to an Excel file, the easiest thing would be to literally just open the .m file in the editor, highlight what you want, copy, and then paste in Excel. I can't really see why you'd ever want to do something like that, but hey, stranger things have happened I guess.
