Customize bapi for sales orders with customer fields

Question

The situation is a following.
Customer has added a structure on table VBAP. They used Append but without include.
Now I have to make a BAPI that will be able to write on those fields. I have used several posts and documentation, but with on change : Instead of passing on BAPE_VBAP, BAPE_VBAPX, etc the original structure, i pass another that is an exact copy.
Could this be the source of the fact that i Dont write anything? The return struct contains tthese :
ORDER_HEADER_IN has been processed successfully
return..:                                     
ITEM_IN has been processed successfully       
return..:                                     
But nothing is shown on vbap

Answer 1

thanks for the reply, but this is something I knew. My problem was whether the structure added to those BAPE_* has to be exaxtly the structure appended to VBAP, or just an identical structure (eg if I appended VBAPEXT to VBAP, should I append VBAPEXT to BAPE_*, or could I use VBAPEXT_copy, which is exactly the same with different name)?
Anyway, we solved the problem and it seems that we can use an identical structure with same name.