Sales: Add backorder items onto existing purchase order

I have recently been on the phone to tech support about this problem and they tell me there is no facility to do what I want to do and indicated that I should submit my idea.

The issues is to do with inventory management and ordering of stock.

Currently I do not maintain stock of items that I sell ie. I only order items from my supplier when a customer orders them from me.

All of my inventory items come from the same supplier.

My process is as follows:

1. Customer orders items
2. Sales Order created on MYOB
3. Client pays for order in advance
4. Order converted to purchase order from supplier
5. PO issued to supplier
6. Items and invoice from supplier arrive
7. PO coverted to bill (purchase)
8. Items checked off as arrived (or on back order)
9. Bill from supplier paid
10. Customer orders converted to invoices and marked off as paid
11. Items delivered to customer.

The problem arises when I have several different customers who order different items at the same time.   In the most recent example I have five different customers who ordered 10 different items from me.   All of the ordered items come from the same supplier.  Thus I created 5 different customer orders and converted them for 5 different PO from the supplier. 

Here is where the new feature could be implemented.   As these 5 PO are all for the same supplier it would be great to merge purchase orders by supplier so I can have ONE PO on the system for the one supplier.   Thuse when the invoice comes in with the items from the supplier, I can match it to the one PO instead of having to work out to which POs it applies.

At the moment I have to work around this by manually creating a NEW PO for my supplier, enter all of the items from the individual POs  and then delete the individual POs - this is doubling up work and taking a very long time to do

Hope that is clear.  If not please contact me for more details