Exit for XK02

Hello,

On calling the Xk02 transaction, if the checkbox - Purchasing data is checked then i would like to check if the current user has access to a specific
role and if yes then he should be allowed to enter the transaction.

If he does not have the role defined for his id then an error should appear and the initial screen is to be displayed again( Subsequent screens are not to be displayed).

Standard authority check does the checks based on copany code, purch org etc but i would like to check it againt a Zrole and then stop the further
processing based on it?

Is there any exit or badi i can use for this purpose. I found a BADI VENDOR_ADD_DATA but that does not seem to help my case. Any suggestions?

Thanks,

Prem