whether the MT940 adapter can generate or expose a per-line sequence number in the CSV

We load SWIFT MT940 bank statements into Transaction Matching through Data Integration, using a Bank File source system with the “SWIFT MT940 Format Bank File Transactions” source application. Data Integration converts the MT940 file to CSV with predefined columns (Transaction Reference Number, Account, Statement Number, Statement Date, Transaction Date, Amount, Transaction Type, Customer Reference, Bank Reference, Bank Text, Bank Text2 to 4, and so on).
We need each transaction line to carry a unique identifier. At present the generated CSV has no sequence or line number column. Statements can contain lines that are identical on date, amount, and references (for example bank fees or batch postings), so a composite key built from the available fields is not guaranteed to be unique.