Import LedgerJournalTrans - How determine the voucher num automatically?

Hello together,

currently I'm trying to import Excel Data into LedgerJournalTrans. I got stuck with the handling of voucher numbers.

I want to integrate the UI functionality (when the user enters lines in a journal), which assigns the voucher numbers.

Example 1: the system switches to a new voucher number if the user enteres 4 rows with a debit amount of 10 and 1 row with a credit amount of 40. The next line will use a new voucher number.

Example 2: If the user enters account num and offset account num, the system will automatically assign a new voucher num in the following row.

I guess the logic is partly placed in the LedgerJournalEngine.

How could this be done in an import class (via x++)? Are there any standard classes which could be used?

Thanks in advance

Sebastian