ePro requisition entry

Has anyone found a way to identify for a requisition line that is entered, if there is an item id, whether ther is a quantity on order or not?  Looking for an easy way to alert a user that this is already on order.  Ideally would like to modify to have a link to a page (surprised one does not exist by item) that would show the orders, open order qty and the approved not yet sourced requisitions.  Thanks in advance for any help!