Hi
I have two ideas in my mind. One of them is already shared by you that we can do this by creating a copying routine and adding this IF condition in it.
Other one is to have separate document types for both sales organization. See your document types structure. In some cases they already have separate document types for each sales organization. If this is so you can maintain different values in both. If this is not so then see the possibility to create separate document types/item category for both sales organization. This setting is there at item level so this could be another thought.
Using userexit is another way to do this but I won't recommend that.
Thank$
