BDOC BUPA_MAIN extension R/3 -> CRM

Hi,

I need to map some fields from KNA1 table in R/3 (customer condition group) to CRM BP master data.

I'am thinking to put then in CRMM_BUT_FRG0041 table in CRM in the fields ATTRIBUTE, ATTRIB_2 ... ATTRIB_5.

My question is which function module or exit can I change, on CRM System, to mapping these fields?

Thanks.

Best regards,

Alexandre Aires