Sub SommBilans(ByVal DateDéb As Month, ByVal DateFin As Month)
Dim FCible As Worksheet, FSourc As Worksheet
FCible = ThisWorkbook.Worksheets(1)
DateDéb = CDate(Feuil1.[DateDéb].Value)
DateDéb = CDate(Feuil1.[DateFin].Value)
FCible.[B14:E20].Value = 1
FCible.[B28:E29].Value = 1
FCible.[B37:E42].Value = 1
FCible.[B50:E51].Value = 1
FCible.[B59:E67].Value = 1
FCible.[B75:E75].Value = 1
While Month(DateDéb) <= Month(DateFin)
Workbooks.Open ThisWorkbook.Path & "\" & Format(DateDéb, "mmm") & ".xls"
Set FSourc = ActiveWorkbook.Worksheets(5)
FSourc.[B14:E20].Copy
FCible.[B14:E20].PasteSpecial Paste:=xlValues, Operation:=xlAdd
FSourc.[B28:E29].Copy
FCible.[B28:E29].PasteSpecial Paste:=xlValues, Operation:=xlAdd
FSourc.[B37:E42].Copy
FCible.[B37:E42].PasteSpecial Paste:=xlValues, Operation:=xlAdd
FSourc.[B50:E51].Copy
FCible.[B50:E51].PasteSpecial Paste:=xlValues, Operation:=xlAdd
FSourc.[B59:E67].Copy
FCible.[B59:E67].PasteSpecial Paste:=xlValues, Operation:=xlAdd
FSourc.[B75:E75].Copy
FCible.[B75:E75].PasteSpecial Paste:=xlValues, Operation:=xlAdd
DateDéb = DateSerial(Year(DateDéb), Month(DateDéb) + 1, 1)
Wend
End Sub