Option Explicit
Sub Verbessert()
Dim rngSummary As Excel.Range
With Worksheets("Zusammenfassung Ergebnisse")
Set rngSummary = .Range("C5:C" & .Range("C" & .Rows.Count).End(xlUp).Row)
If rngSummary.Row < 5 Then Set rngSummary = Nothing
End With
Dim rngControl As Excel.Range
With Worksheets("Steuerungstabelle")
Set rngControl = .Range("D5:AE" & .Range("D" & .Rows.Count).End(xlUp).Row)
If rngControl.Row < 5 Then Set rngControl = Nothing
End With
If rngSummary Is Nothing _
Or rngControl Is Nothing _
Then
Exit Sub
End If
rngSummary.Formula = "=VLOOKUP($A5," & rngControl.Address(True, True, External:=True) & ", 2, FALSE)"
rngSummary.Value = rngSummary.Value
End Sub