How Expense Module can select correct Bank Accounts for ACH and Checks?

Hello! We have this need and was wondering how we can do this. Out client has dedicated bank accounts setup for ACH and CHECKS under same Setid. Expense options reflect only bank and a default payment method (CHK). When we create transactions for an employee whose profile is setup as ACH, the system is selecting the bank account tied at expense option level (which is incorrect because it is choosing CHK bank information) and staging that for paycycle. How do we make the system flexible so we can make ACH and Check payments that are tied to respective bank accounts.?