Actually, this was a really poor description of what I wanted, which was....
 
In AR-A, type in a customer code, hit the Shipments icon (little UPS truck), brings up the INV_HIST_HDR form.  I wanted to add Customer PO number to that, and somehow I managed to do that without messing things up!  Hooray!  I even managed to add Customer PO number to the sort list, although it does take a while to resort the list (maybe 30 seconds....maybe a re-index is in order).
 
Now the pie in the sky request from Sales - what they do is go in to this screen as described above to find our invoice and SO numbers based on the customer PO number  -  
 
1st they would love that screen to show the SO notes - (I'm going to investigate that) - but what they would LOVE is to be able to double click the line for that order and be taken directly to the invoice for that order (wishful thinking I guess)

Believe it or not, I actually figured that out myself (scary).  Although I don't totally understand it yet, I hit the drill down arrow when I had a certain order highlighted and came up with the INV_HIST_LINE drill down.  Is there any way in that report to get the SO notes for that order??

If you drill down to shipments and highlight an order did you know you could print the SO, Packing list and/or invoice using the little document button (right next to the open/closed door)?

Allen, I tried it again and when I use the shipments lookup and drill down to invoice lines they match the invoice printed when I use the document printer.  They are both correct,  whether or not I do a sub-string search on the PO field- which sounded like a good add to me- thanks Mike!  
We do not have notes turned on yet.