Adding a push button in the PF status

Hi,

My requirement is to add a push button in the PF status of the second screen of transaction WCTL.

I have searched for user exits , badi, enhancement points and none of them are there for this transaction.

When i try to copy the program, and modify the Z program,its getting activated but when i run the custom transaction, its throwing number of errors.

Any pointers about adding the push button to this transaction would be helpful.

Thanks,

Avanish Joshi