Enhancing LORD API - Correspondence Language

Hi experts,

i would like to make the field correspondence language of the customer available in the head of my quotation:

Field: ADDR1_DATA-LANGU

Program: SAPLV09C

Number: 5000

Is it possible to map my new Z-Field for the correspondence language in CRM (AET enhancement) directly with the upper field?

Where would i need to make the codding for fetching the right partner ?  BADI ENH_SPOT_LORD ?

How would the mapping tables look like in ERP ? (LORD_MAPPING, LORD_MAPPING_RO)

OR is the only way to create a new Z-Field in ERP as well, enhance the screen to add this Z-Field and do the sync between the Z-Field in ERP and the field ADDR1_DATA-LANGU in some user exit?

This new z-field in ERP will then be mapped with the crm z-field.

Thanks in advance for any hints.

Wladimir