I still don't see what your problem is.

If the only reason your opening the CSV file in Excel is to edit three values ( or a hundred),
then you can do the same thing with any text editing program, such as Notepad, Wordpad, or Jedit.
A CSV (Comma Separated Values) file, is a simple Text file where the Values have been separated by commas. No special formatting required. As long as you don't mess with the comma's you should have no problems.

If you need an additional copy, then simply do a save as with a new name.

Or am I missing something??