Auto Approval for a specific Expense Type

Under Business Unit 2 in the Business Unit configuration for expenses, you can set a Monetary Amount Threshold to automatically approve an expense report of a specific amount. We only want Mileage under $25 to automatically approve. Is there any way to select a specific expense type under a specific monetary threshold or is it all or nothing for the configuration set up?

Thank you for any ideas/assistance!

Alana Lehr