Hallo Stefan,
thanks a lot for you help !
In the last two days I did some tests ... but without success.
When I read the data from the table BSIS I filter by the column AUFNR.
In the following link Verzeichnis SAP Tabellen Übersicht Teil I - DV-Treff
I found the tables COBK and COEP.
In these two tables (but also in the others CO-Tables) I do not see the column AUFNR.
Regards.
Miche