User Exit PPCO0018 for transaction COR2 doesn't work.

Hello.

I have following problem.

I want to control changes in process order header in transactions COR1/COR2.

I found User Exit PPCO0018 but it works only in CO02 not in COR2. How to activate this user exit to work in COR2 transaction or is another user exit similar to PPCO0018 which work in process order transaction COR1/COR2?

Thanks for help.

Bogdan