Authorization check on PO account assignment

Hi,

I would like to incorporate authorization check on PO account assignment (cost centre and internal order fields). I have tried SU24 and SU22 but this is not possible when I include authorization object K_CSKS to transaction ME21N.

Is there any other means where I can check if the person who creates the PO has access to the cost centre / IO specified in the account assignment section of the PO?

Please assist.

Thanks in advance.