Controlling the workflow list of users available for Approval delegation/transfer

We have implemented Oracle Workflow for our EBS GL journal entries.  When a user enters a journal entry, they click on an Approve button to send the entry through workflow approval.  Here is the issue we are having.  An approver knows he/she is going to be out of the office.  So they go in to either Delegate or Transfer their approver responsibility to another person.  When the list of users for them to select from populates, it contains all users set up in EBS GL not just the users that have been designated as an approver and have an approval