MM intercompany account determination

Question

Hallo Everybody,
when purchasing (ME21N) I would like to use a different G/L account for intercompany and third party purchases without creating a separate plant or using split valuation
For stock postings my FI substitution based on trading partner kicks in during goods receipt but when I purchase goods using a CO object this does not work because commitments with the wrong accounts are used. OK, during goods receipt everything works well from then on but the wrong account is displayed on the PO.
I tried to solve this problem using a CO substitution with the same logic. When debugging I can see that the right G/L account is chosen but it is not put on the purchase order. When saving the wrong account is of course chosen. I can change the account manually in the purchase order, then the CO object will be posted with the newly entered G/L account.
Do you know of any other automated way to solve this problem?
Best Regards

Answer 1

Find it hard to understand on why you are trying the re-invent the wheel. Split Valuation is the solution for your requirement, if that cannot be used, then creating a new solution will be creating the split valuation logic without naming it as such. Not sure what is the value of doing a such costly, error prone process when you have tested and proved solution on hand.