Comment 3 for bug 1018002

Malac, regarding your scenario, do you have the user permissions to change the file permissions in your environment, or are you looking to do this from an end-user/cannot edit file permission perspective?

As well, does the following WORKAROUND provide a solution for your situation:
Allow read/write/execute permissions to the file for the appropriate users -> open file -> highlight cells one would like to have modifiable by users -> secondary click one of the highlighted cells -> primary click Format cells... -> tab Cell Protection -> uncheck Protected -> button OK -> secondary click the desired sheet -> Protect Sheet... -> check Protect this sheet and the contents of protected cells -> type and confirm password -> button OK