Update fields BSEG-KKBER and BSID-KKBER (Credit management)

Hi,

I have a requirement where i need to update the fields:

BSID-KKBER

BSEG-KKBER

I have already been been looking at BAPI, FM but i have found nothing so far.

Is there anyone that has a solution or suggestion?

Thanks a lot in advance.