Inter-company invoice on sales minus mark down to our group company.

Hi Gurus.

We have a scenario where Order is Booked in OU1(US) and is warehouse used for shipping is OU2 (Switzerland).

In this case assume item on sales order has Sales price 100 $ . End customer AR will be generated for 100 $  however there is a requirement where we need the intercompany invoicing to happen at 10% discount. 

Basically we have a requirement, wherein we will bill our customer on sales price and build inter-company invoice on sales minus markdown i.e. 10%  to our group company.

Any help will be much appreciated