Funktion in Makro aufrufen

Function num_einheiten(land As String)
' Gibt an wieviele Einheiten in dem Land stehen
Application.Volatile
Dim b As Range
Dim a As Integer
With Worksheets("Eingabe").Range("D21:D62")
Set b = .Find(land, LookIn:=xlValues)
End With
num_einheiten = WorksheetFunction.Max(Range(Cells(b.Row, 5), Cells(b.Row, 10)))
End Function

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
Dim a As Integer
Application.EnableEvents = False
'Länder befüllen in Spalte V
If Not Intersect(Target, Range("N36")) Is Nothing Then
Sheets("Eingabe").Cells(36, 17) = ""
a = WorksheetFunction.Min(num_einheiten(Range("N36")), 3)
Range("N39").Value = a
End If
Application.EnableEvents = True
End Sub