In the AP workflow is it possible to show/edit/add project information (POET) to the invoice line

trying to implement iSupplier self service invoicing but then allow a field user to add project information to that AP Invoice in the workflow.   I don't see Project information exposed in the AP Invoice workflow .  any ideas how to expose this?

Actor	System	Action	Result
Supplier	iSupplier	Self enter non-PO Invoice (no   POET info)	Invoice inserted into AP   Invoice interface tables
Concurrent manger	AP	Job to import Invoices into AP	Supplier invoice in AP ,   unapproved, no POET
AP User	AP	(optional step) add detail to   the unapproved invoice to help guide workflow routing .   Initiate   workflow routing	Workflow engine routing AP