With Range("A1")
.FormulaR1C1 = "=SUMPRODUCT((R1C=INDIRECT(""'[""&Fich_N1_act&""]Feuil1'!$I$5:$I$700""))*(INDIRECT(""'[""&Fich_N1_act&""]Feuil1'!$F$5:$F$700"")=RC5),INDIRECT(""'[""&Fich_N1_act&""]Feuil1'!$K$5:$K$700""))"
Do While Application.CalculationState <> xlDone: DoEvents: Loop
.Value = .Value
End With