Save all changes on same file

[jmolero]

I use a popular CMS and make my changes on a single file called "mymod.css" wich overwrites whatever is above in the inheritance.

I would like to save all my changes made on the inspector at that same file even if the style rule I'm editing comes from another file.

Is it possible to add a default file at wich save changes?

Like adding the flag:

autosave -f /pathto/mymod.css

Thanks