Well, based on the constraints that you have put on the solution. I would either go with option 2 or 3. There is not an elegant solution to this at all.
I would however, lean towards your third option, as a "one time" fix to get the files linked, so that the path between them is known, and you are not dynamically adding path information into every query.
note
I'll just mention, but I'm sure you already know this, that if you are looking at doing something like this, it just feels wrong to be doing it with Access, let alone access 2000 at this time for client deployments. I would strongly recommend additionally truly evaluating the solution and see if you can either merge to one, or possibly move to SQL Server Express or something that you could send off to the user as an installer