Can PO approver be prevented from approving accounts not in his/her business unit?

We are trying to determine whether or not to implement Approval Routes. It looks really good for most of our requirements, but one thing has come up that I don't know if JDE can handle it or not (with or without customization). The approval routes we have set up are based on business unit (not branch plant). We have created versions of PO entry to use specific approval routes. Here's where it gets hairy: We would like to prevent an approver from approving a PO that has an account outside of his/her business unit.  Has anyone had any experience with