VBA boucle, recherche cellule vide

Sub minMax()
    Dim shS As Worksheet, shD As Worksheet
    Dim dercol As Long, derlig As Long, col As Long, lig As Long
    Dim cpt As Long, mini As Double, maxi As Double, vide As Boolean
    Set shS = Worksheets("Feuil2")
    Set shD = Worksheets("Feuil3")
    With shS
        dercol = .[IV1].End(xlToLeft).Column
        For col = 5 To dercol
            vide = False
            mini = 9 ^ 99
            maxi = -9 ^ 99
            derlig = .Cells(65536, col).End(xlUp).Row
            For lig = 2 To derlig
                If .Cells(lig, col) = "" Then
                    vide = True
                    Exit For
                Else
                    If .Cells(lig, col) < mini Then mini = .Cells(lig, col)
                    If .Cells(lig, col) > maxi Then maxi = .Cells(lig, col)
                End If
            Next lig
            If vide Then
                shD.[D6].Offset(cpt, 0) = "default"
                shD.[D6].Offset(cpt, 2) = "default"
            Else
                shD.[D6].Offset(cpt, 0) = maxi
                shD.[D6].Offset(cpt, 2) = mini
            End If
            cpt = cpt + 1
        Next col
    End With
End Sub