Option Explicit
Public Sub Copie_Ligne()
Dim WbSource As Workbook, WbDest As Workbook, Wb As Workbook
Set Wb = "ResReportKON May2018.xlsx"
Set WbSource = Workbooks.Open(Wb)
Set WbDest = ThisWorkbook
WbSource.Sheets("May18FORECAST").Range("c4:cg4").Copy
WbDest.Sheets("Mai2018").Range("c3").PasteSpecial Paste:=xlPasteValues
Application.CutCopyMode = 0
Application.Goto WbDest.Sheets("Mai2018").Range("a1")
ActiveWorkbook.Close False
End Sub