How to simulate ATP check in user exit

Dear Expert,

as we konw, when we change so item requirement type, the ATP checking rule will be re-determined. see below:

change requiremennt from ZJ1->ZJ0, checking rule is changed from AE->A.

My problem is: if i set requirement type = ZJ0 in user exit :  userexit_move_field_to_vbap.

but the checking rule is still AE, could you please help on this? Thanks a lot.