I had a similar request, but decided to use AR_InvoiceHistoryHeader and AR_InvoiceHistoryTracking instead. Using data entry files becomes problematic if user fails to generate export prior to updating, or generates file then cancels/edits shipment.
Ended up creating a Crystal report with parameter to only export that days invoices ({AR_InvoiceHistoryHeader.DateUpdated} = CurrentDate), then scheduled it to run daily.