How to convert a MT940 bank file to CSV readable format for data load

Here's an example to get you started.

'main
ConvertMT940ToCSV("path_to_MT940_file.sta", "output.csv")

'class functions
Private Sub WriteToCSV(transactions As List(Of String), filePath As String)
    Using writer As New StreamWriter(filePath)
        writer.WriteLine("Date,Credit/Debit,Amount") ' CSV Header
        For Each transaction As String In transactions
            writer.WriteLine(transaction)
        Next
    End Using
End Sub

Private Function ParseTransaction(transactionLine As String) As String
    ' Simplified parsing: Extract date and amount as example
    Dim pattern As String = "^\:61\:(\d{6})(C|D)(\d+,\d{0,2})"
    Dim match As Match = Regex.Match(transactionLine, pattern)
    If match.Success Then
        Dim dateValue As String = match.Groups(1).Value
        Dim creditDebit As String = match.Groups(2).Value
        Dim amount As String = match.Groups(3).Value.Replace(",", ".") ' Change comma to dot for CSV
        Return $"{dateValue},{creditDebit},{amount}"
    End If
    Return String.Empty
End Function