Exit / or BAdI in Plan Order (CO48)

Hi all,

I want to check quantity in Plan order (CO48). My requirement is If open quantities less than 0 will occurs error that quantity is not allowed. I was used BAdI WORKORDER_UPDATE, DATA_EXTENSION_CK in any method and also Exit EXIT_SAPLCOIH_009, EXIT_SAPLCOZV_001, EXIT_SAPLCOKO1_004 but no one suitable with my requirement. Almost suitable with BAdI WORKORDER_UPDATE in BEFORE_UPDATE method, but I got short dump (COMMIT WORK processing cannot be interrupted) after error message appears.

Any idea or where I can find structure of Open quantities in CO48 temporary stored?. Here attached that I mean of CO48 transaction.

Thanks.