Might help us more if you post your code, using code tags (# on menubar).
If you are using the Form Delete event and incorporate error handling, IIRC this event should cycle for each record being deleted, and if it can't, it would raise an error (3379?). In that case, you should be able to branch one way for no error, and the other when it errs. Not sure what that would be; I can't tell if it would just be a Cancel for the deletion, or some other operation on the record.
I guess you just can't let Access delete what it can and trap the usual error message for those it can't? Not sure I'm following your posted procedure. If you're moving records to another table as a form of deletion, why not just flag the record in the original table somehow, as in a yes/no field or DateDeleted field?
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.