HU create BADI/ User exit

Hello Experts,

I want to update a Z-field in table VEKP at the time of creation of HU through Tcode COPP1.

I found BADI_HU_SAVE but here IT_HEADER is a Importing parameter and hence cannot be changed.

Can anyone please suggest some other BADI or Exit which have structure of VEKP for transaction COPP1.

Thanks in advance.

Thanks & Best regards

Ankur