If you try to overwrite a file with permissions issues, you will always have problems. For example, if you create a file (or someone else does) as admin and then try to overwrite it as Guest, it won't work. Unless, you can't avoid it, why not just add 1,2,3, etc to the end of the filename and keep multiple copies?
Chris R Mead
The opinions expressed herein are my own personal opinions and do not represent my employer's view in any way.