VBA - Nested Class - ms-access

Question

[Edited the code]
Sorry for newbie question. I was trying to test nested classes in VBA for Excel but got error message. Can anyone help me understand why? Thank you!
Inside class:
' CLASS MODULE - cInside
' Member variables
Private m_Value As Integer
' Properties
Property Get Value() As Integer
Value = m_Value
End Property
Property Let Value(i As Integer)
m_Value = i
End Property
' Methods
Sub init()
m_Value = 0
End Sub
Sub Inc()
m_Value = m_Value + 1
End Sub
Outside class:
' CLASS MODULE - cOutside
' Member variables
Private m_Num1 As New cInside
Private m_Num2 As New cInside
' Properties
Property Get Num1() As cInside
Num1 = m_Num1.Value
End Property
Property Get Num2() As cInside
Num2 = m_Num2.Value
End Property
Property Set Num1(i As cInside)
Set m_Num1 = i
End Property
Property Set Num2(i As cInside)
Set m_Num2 = i
End Property
Main program:
Sub Main()
Dim o As New cOutside
Dim i As New cInside
i.Value = 9
i.Inc
Debug.Print i.Value '<-- this works
Set o.Num1 = i
o.Num1.Inc '<-- object variable or with block variable not set
Debug.Print (o.Num1.Value)
End Sub
Thank you again!

Answer 1

n.Num1 returns an Integer, which isn't an instance of cInside, and therefore doesn't have an Inc member, which makes it an invalid qualifier for the compiler to complain about ;-)
Your cOutside class needs to expose it somehow:
Property Get ComposedObject1() As cInside
Set ComposedObject1 = m_Num1
End Property
Then the calling code could do this:
n.ComposedObject1.Inc
I called that "composed", because what you're doing isn't "nesting", but "composition". VBA doesn't supported nested classes, which would be a class module defined inside another class module, like so:
Class Outside
'... members...
Class Inside
'...members...
End Class
End Class
VB.NET can do that, but in VBA 1 class module can only define 1 class.