AR aging basing on Invoice date

Currently client gets AR aging based on Due Date. For audit purpose they need AR Aging based on Invoice Date. During SAP implementation they were instructed to use document date as invoice date and generate a dump from FBL5N and do the aging. However this does not work for balancing items as the document date changes to the date on which the partial clearing of that item was done. This is not acceptable to auditors.

Please help.

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