1. Open the existing auto-generated batch
2. Select Tools, Automatically Generate Transactions/Payments from the menu bar
3. Change the Transaction due on or before date to include the additional gifts
4. Change the Gift Types and/or Pay Method as required
5. Click Generate Now - this will include the additional gifts

If the transmission file has already been created but not sent, you will get a warning and will have to create another transmission file. Please note this cannot be done if the transmission file has been sent to the bank.