Inventory Allocation workflow

[BBaes]

Hello All!  I have a really hard question! I have a list of sales orders, a list of purchase orders, and a list of stock. I am trying to line up what will be consumed for each sales order by contract date of the sales order. Stock must be consumed first. I have been able to sort them by date and deplete the stock, but I cannot figure out how to then fill in the missing gaps with the Purchase Orders. Help! I have just attached the data because the work flow is just a data input and sort so far. I don't know where to start.  I hope this makes sense. 

Sales Order	S.O. Part #	Contract Date	Sales Order Qty	Stock	Purchase Order	P.O. QTY	PO Part #	Purchase Order Date
1	141516	1/5/2023	2	1	450501	2	141516	1/6/2023
2	151617	1/6/2023	3	4	450502	2	141516	1/8/2023
3	161718	1/7/2023	4	3	450503	2	141516	1/10/2023
4	181920	1/7/2023	2	0	450504	2	151617	1/11/2023
5	212223	1/9/2023	5	0	450505	2	161718	1/10/2023
6	161718	1/10/2023	4	3	450506	2	161718	1/12/2023
7	161718	1/15/2023	4	3	450507	4	161718	1/14/2023
					450508	1	161718	1/16/2023
					450509	2	181920	1/17/2023
					450510	1	151617	1/13/2023
					450511	2	212223	1/11/2023
					450512	3	212223	1/12/2023
Result
Sales Order	S.O. Part #	Contract Date	Sales Order Qty	Stock used	Purchase Order Used	Purchase Order	Purchase Order 2	Purchase Order 3
1	141516	1/5/2023	2	1	1	450501
2	151617	1/6/2023	3	3	0
3	161718	1/7/2023	4	3	1	450505
4	181920	1/7/2023	2	0	0	450509
5	212223	1/9/2023	5	0	0	450511	450512
6	161718	1/10/2023	4	0	4	450505	450506	450507
7	161718	1/15/2023	4	0	4	450507	450508

[BBaes]

Sales Orders 4 and 5 should of had Purchase Orders used as 2 and 5.