Fomula to list order numbers and relevent stock movements

Hi

I've set out a spreadsheet to help with stock control at work and need help on one final formula that I cannot solve myself.

Basically I have one worksheet called stock and another worksheet called stock out, now I've linked them both up for the total stock movements out over the month. However I need to get it so that individual PO movements from the stock out show up on the relevant PO on stock. For Example

Stock Worksheet
Part 1 12pcs in total

Stock out
Part 1 3pcs from 82012 7pcs from 86483

As you can see the total stock is easily linked in, however I need to know how much has come from each PO to create that total, so that, for example,on the stock worksheet it would show that 3pcs of part 1 came from PO 82012 and 7 from 86483 and so on.

Any help would be greatly appreciated.

Thanks