In case of AR Invoices how can we have the Conversion Rate Date same as Sales Order Date

In case of AR Invoices we want to capture the Conversion(Exchange Rate) Date same as Sales Order Date.

System Behavior: At present it is directly getting derived as the Date of Dispatch of Sales Order i.e Invoice Creation Date(When we run the Import Auto Invoice lines after shipment)

Expected Solution: When the Invoice is created after the Shipment.. System should derive the exchange rate Date from the Sales Order Date.

Pls let us know if there is any possible workaround to achieve the above requirement.