My suggestion of a better solution would be better tools. For instance, when viewing or editing the code, a call to CopyFile should appear something like
with the "[from]" and "[to]" parts not being actual tokens that are part of the source file, but annotations that appear to assist the developer. They would appear as little badges, non-editable or selectable, with distinctions in their display to make it clear they are UI elements rather than part of the source code.
