n00b help with referencing files

[nilamo]

I don't think you need os.walk(), since you're not recursing into those directories (it would work, it's just more complicated than you need).  glob.glob() could do this just fine.

import glob, pathlib

destination = "/this/other/different/path/to/{0}/filetomodify"

for ref in glob.glob("/this/path/to/*/refFile"):
   path = pathlib.Path(ref)
   folder = path.parent.name
   with open(ref) as refFile:
       with open(destination.format(folder), "w") as file_to_modify:
           for line in refFile:
               # line formatting here
               print(line, file=file_to_modify)