Requirement to send an approval notification (response required) to other person that is not in the

Hi Gurus,

I have a requirement where I need to send the PO approval notification (based on item category) to other person who is currently not in hierarchy.  If Item category lies in a list of categories then a Final PO approval notification needs to be sent to other person who is currently not in hierarchy. This notification needs to be a Final notification.

We are using Employee/Supervisor Approval Process for PO approval and we cannot use AME. Is it possible if yes, how?

Thanks in Advance.

Nitin