Програма для нахождения разных цифр числа - VB

Option Explicit
 
Private Sub Form_Load()
    Debug.Print isDiffDig(1238743)
End Sub
Function isDiffDig(n As Variant, Optional q As Long) As Boolean
    q = Len(CStr(n)) - 1: n = Replace(CStr(n), Left$(CStr(n), 1), vbNullString)
    If Len(n) = q Then If Len(n) Then isDiffDig = isDiffDig(n) Else isDiffDig = True Else Exit Function
End Function