Price Package Purchase Orders

Summary:

Client has requirement to create PO s where PP total amount is already fixed and unit price is back calculated.

Content (required):

For Supplier A , PO can be of value 400 $

So when items X,Y,Z,S on PO for quantity 1 EACH.Unit price should be 400/4= 100$. Is there any way to achieve this

Version (include the version you are using, if applicable):

Code Snippet (add any code snippets that support your topic, if applicable):