customer Tab in IB51

Hi Friends,

We have a new requirement to add customer Tab under the lower -leve lobject in transaction IB51 ( next to Material, equipment)

We tried to modify using screenexists and User exists. Sicne standard SAP does not support creating new tab, we could not add

We tried to add the object KUNDE in the Maintenance view V_T371D, but we have to add the class and function module to activate this tab in IB51

Could you provide your valuable input on how to achieve this either by creating new tab or appending new fields on the IB51 transaction

regards,

santosh