I need to do a de-dupe on a set of records. Two groups were brought in with different External ID's for each contact. I need to merge the contacts, but export the External ID that was kept and the External ID that was dropped. Having the First Name/Last Name would be bonus. This way, when I bring in additional data linked to an external ID, I can pre-write the corrected existing external ID from the map.
Contact A has an External ID of 123. Contact B has an External ID of 456. Contact A and B are the same person, but has two different External ID's from separate systems. I need to create a mapping, an exported CSV file, that maps 456 to 123, so that when I later bring in Note C related to Contact B via External ID 456, I can re-write the External ID to 123 and have Note C imported to Contact A with External ID 123.
Unfortunately, I don't see any kind of Export on the de-duping pages. I'm hoping that I am just missing it. Any ideas how one might accomplish such a task without going line by line and copy/pasting to an Excel file? (We're talking thousands here.)
Clear as mud yet?
Wordpress 4.5.3, CiviCRM 4.7.8 (Yes, I'm aware of the current de-dup flipping bug that is being fixed in 4.7.9.)