user exit for ME51N,ME52N, issue with account assignment

Hello Experts,

I'm working on a user exit for transactions me51N and me52N in order to set restrictions for some fields on the account assignment data section (assets, orders and wbs elements). I already found the user exit MEREQ001 (EXIT_SAPLMEREQ_005), the problem here is that I’m only able to see the item data but can’t find the account assignment data related to it. How can I get those fields inside the user exit?

Any suggestions are welcomed... Helpful answers will be rewarded for sure…

Thanks in advance,

George