I am importing data from Excel forms into Access tables.
I want each form to have a unique number, such as
RFI_001, that cannot be duplicated in Access.

Example problem:
RFI_001 is imported into Access, then that Excel file is
emailed out to another party for a response.
When the response is received, I want to replace the
previously imported RFI_001 with the new one--the one
with the response.

If I make RFI the key field in Access, the
subsequent "responded-to" RFI_001 will not be allowed to
be imported and overwrite the originally imported RFI_001.
(I still want to maintain the integrity of the unique
number RFI_001.)

Is there a way to do what I'm trying to do?

Thanks for your help.

John