Thanks a lot!!
We copy the class CL_BUPA_IL_HEADER_SEARCH, and then:
Go to SPRO:
SAP Implementation Guide
Customer Relationship Management
CRM Cross-Application Components
Generic Interaction Layer/Object Layer
Component-Specific Settings
Extend Object Model for Business Partner
Here add a new entry for object BuilHeaderSearchNew and enter the Z class created above.
We adapted the Z class (Methods: CHECKED_SEARCH_AVAILABLE, GET_RESULT_TABLE, etc).