How to create global field for Customer Create XD01

Hi All,

I have added a custom code in the user exit ZXF04U01( XD01 - Customer create), Now I need to create a global field value, is there any include file where I can declare customer create related field.

Include function INCLUDE MF02DTOP is already there but I am looking where customer specific fields can be declared.

Thanks in advance for your help.

Avanti