Fusion de fichiers csv dans un seul fichier à plus de 1 000 000 lignes

Sub ImportCSV21WBK()
'source:[15/7/13] - jindon
'++++++++++++++++++++++++++++
'ici on recopie chaque CSV dans une feuille distincte dans un même classeur
Dim rep$, fCSV$, wb As Workbook: Set wb = ActiveWorkbook
With Application.FileDialog(msoFileDialogFolderPicker)
If .Show Then rep = .SelectedItems(1) & "\"
End With
Application.ScreenUpdating = False
If rep = "" Then Exit Sub
fCSV = Dir(rep & "*.csv")
Do While fCSV <> ""
    With Workbooks.Open(rep & fCSV)
        .Sheets(1).Copy after:=wb.Sheets(wb.Sheets.Count): .Close False
    End With
    fCSV = Dir
Loop
End Sub

Sub ImportMultipleCSVin1Sheet()
'source: [201213] - jindon
Dim strPath$, strFile$, temp
Dim rep$, fCSV$, wb As Workbook: Set wb = ActiveWorkbook
With Application.FileDialog(msoFileDialogFolderPicker)
If .Show Then rep = .SelectedItems(1) & "\"
End With
    strPath = rep: strFile = "AllInOne.csv"
    temp = Shell("cmd.exe /c copy " & strPath & "*.csv " & strPath & strFile)
    With ActiveSheet
        With .QueryTables.Add(Connection:="TEXT;" & strPath & strFile, _
            Destination:=.Range("A1"))
            .Name = Replace(strFile, ".csv", "")
            .TextFileParseType = xlDelimited
            .TextFileTextQualifier = xlTextQualifierDoubleQuote
            .TextFileConsecutiveDelimiter = False
            .TextFileTabDelimiter = False
            .TextFileSemicolonDelimiter = True
            .TextFileCommaDelimiter = False 'True
            .TextFileSpaceDelimiter = False
            .TextFileColumnDataTypes = Array(1)
            .TextFileTrailingMinusNumbers = True
            .Refresh BackgroundQuery:=False
        End With
    End With
    Kill strPath & strFile
End Sub