Sub ResizePrim()
Dim Col1 As New Collection, Tp
ReDim Tp(1)
Tp(0) = Item ' Записываем значение Item
Tp(1) = Key ' Записываем дубликат ключа
Col1.Add Tp, CStr(Key) 'Добавляем элемент коллекции в виде массива в коллекцию
XX = Col1(1)(0) ' Возвращаем значение Item
ZZ = col(1)(1) ' Возвращаем дубликат ключа
End Sub

Option Explicit

Private Declare PtrSafe Sub CopyMemory Lib "kernel32.dll" Alias "RtlMoveMemory" (Destination As Any, Source As Any, ByVal Length As LongPtr)
#If Win64 Then
    Private Const ptrSz = 8
    Private Const varSz = 24
    Private Const collPtrOffset = 40
#Else
    Private Const ptrSz = 4
    Private Const varSz = 16
    Private Const collPtrOffset = 24
#End If

Private Sub Пример()
    Dim Coll As New Collection, elem
    Dim i&
    Coll.Add "item1", "key1"
    Coll.Add "item2", "key2"
    Coll.Add "item3", "key3"
    For i = 1 To Coll.Count
        Debug.Print "Key: ", CollKey(i, Coll)
        Debug.Print "Item: ", Coll(i)
    Next

End Sub

Private Function CollKey(ByVal Index As Long, Col As Collection) As String
    Dim i As Long, Ptr0 As LongPtr, Ptr As LongPtr, Key As String
    If Col Is Nothing Then Exit Function
    Select Case Index
    Case Is < 1, Is > Col.Count: Exit Function
    Case Else
        Ptr = ObjPtr(Col)
        For i = 1 To Index
            CopyMemory Ptr, ByVal Ptr + collPtrOffset, ptrSz
        Next    
        CopyMemory ByVal VarPtr(Key), ByVal Ptr + varSz, ptrSz
        CollKey = Key
        CopyMemory ByVal VarPtr(Key), Ptr0, ptrSz
    End Select
End Function