I know this may be improper to say, but I do not think this is possible using normal Excel formulas. You can probably get really fancy and pull this off, but why? The INDIRECT() formula would normally be the way to go for something like this, but it only works for external references if the externally referenced workbook is opened. There are 2 simple solutions I see here:

1) Pre-link to all of these cells in a hidden or veryhidden tab to create a vlookup list that can be used when the name is changed.
2) Program it in VBA

I personally prefer the second approach and can code it for you if needed. Since it sounds like other things are running on macros, I believe this would be a good option.

Thanks!