RE: Refresh Docs and Modified By Stan Rogers 8.Jan.18 04:48 PM a Web browser Notes Client All ReleasesAll Platforms
You can't. That's part of the Notes/Domino security system. Whoever changed the document is recorded as changing the document. You can run an agent using a different identity (either by signing in with a different user ID or by using a different agent signer/runner for scheduled agents), but that only changes the "who" that's recorded as changing the documents. You can't leave the old ModifiedBy intact if you're modifying documents.
You would need to use a separate field to record who the last end-user to touch the document was.