BADI/BAPI or other application for update VBRK with append structure?
I will insert an append structure to VBRK with only a field (a vbeln-type field). Ok, actually I have made modifications to SAPMV45A on the user exit MV45AOZZ for get the contract number from the order written on VA03 transaction and show it on a screen belongs that. Just I've gotten the contract number from the order number, and I wish to put it on VBRK (in the apppend structure field), considering that VBRK-VBELN is the 'WHERE' condition for what row is the correct for place their contract number (it is, assign the contract number, on VBRK, for the order number that user writes on VA03).
Is it a good idea to write an UPDATE sentence, inside the user exit, for doing the above? Can you tell me what BADI / BAPI can help me, rather than the UPDATE sentence?