Dim SD() as UserType
Dim In() as Double
Dim Out as Double
Dim Sigma() as Double
'..............................
' Методы класса
'.............................
Public Sub ArrJobWrapper(...)
 Call ArrJob(SD() as UserType, Sigma() as Double, ...)
End Sub

Option Explicit

Private Declare Sub CopyMemArrArr Lib "kernel32" Alias "RtlMoveMemory" ( _
   Destination() As Any, Source() As Any, ByVal Length As Long)

Private m_Data() As Long

Public Sub InitData(ByVal nUBound As Long)
 Dim i As Long
 ReDim m_Data( 0  To nUBound) As Long
 For i =  0  To nUBound
    m_Data(i) = i
 Next i
End Sub

Public Sub PrintData()
 Dim i As Long
 If (Not m_Data) <> - 1 & Then
    For i = LBound(m_Data) To UBound(m_Data)
       Debug.Print i, m_Data(i)
    Next i
 End If
End Sub

Public Function GetDataRef() As Long()
 CopyMemArrArr GetDataRef, m_Data,  4 
End Function

Option Explicit

Private Declare Sub CopyMemArrAny Lib "kernel32" Alias "RtlMoveMemory" ( _
   Destination() As Any, Source As Any, ByVal Length As Long)

Public Sub Test()
 Dim d As CData
 Set d = New CData
 d.InitData  5 
 d.PrintData
 
 Dim a() As Long
 a = d.GetDataRef 'Получить ссылку на массив
 ProcessArray a   'Обработать массив
 d.PrintData      'Убедиться, что изменения затронули объект
 
 CopyMemArrAny a,  0 &,  4  'Обязательно очистить ссылку на массив!
End Sub

Private Sub ProcessArray(x() As Long)
 Dim i As Long
 ReDim Preserve x(LBound(x) To UBound(x) +  10 ) As Long
 For i = LBound(x) To UBound(x)
    x(i) =  100 & + i
 Next i
End Sub

Option Explicit

Private Declare Sub CopyMemArrArr Lib "kernel32" Alias "RtlMoveMemory" ( _
   Destination() As Any, Source() As Any, ByVal Length As Long)
Private Declare Sub CopyMemArrAny Lib "kernel32" Alias "RtlMoveMemory" ( _
   Destination() As Any, Source As Any, ByVal Length As Long)

Private m_Data() As Long

Public Sub InitData(ByVal nUBound As Long)
 Dim i As Long
 ReDim m_Data( 0  To nUBound) As Long
 For i =  0  To nUBound
    m_Data(i) = i
 Next i
End Sub

Public Sub PrintData()
 Dim i As Long
 If (Not m_Data) <> - 1 & Then
    For i = LBound(m_Data) To UBound(m_Data)
       Debug.Print i, m_Data(i)
    Next i
 End If
End Sub

Public Sub GetDataRef(Ref() As Long)
 CopyMemArrArr Ref, m_Data,  4 
End Sub

Public Sub ClrDataRef(Ref() As Long)
 CopyMemArrAny Ref,  0 &,  4 
End Sub

Option Explicit

Private Sub ProcessArray(x() As Long)
 Dim i As Long
 ReDim Preserve x(LBound(x) To UBound(x) +  10 ) As Long
 For i = LBound(x) To UBound(x)
    x(i) =  100 & + i
 Next i
End Sub

Public Sub Test()
 Dim d As CData
 Set d = New CData
 d.InitData  5 
 d.PrintData
 
 Dim a() As Long
 d.GetDataRef a 'Получить ссылку на массив
 ProcessArray a 'Обработать массив
 d.PrintData    'Убедиться, что изменения затронули объект
 d.ClrDataRef a 'Обязательно очистить ссылку на массив!
End Sub

Option Explicit

Public Type UserType
   Index As Long
   Value As Double
End Type

Public Sub ArrJob(SD() As UserType, Sigma() As Double, ByVal nLen As Long)
 Dim i As Long
 ReDim SD( 0  To nLen -  1 ) As UserType
 ReDim Sigma( 0  To nLen -  1 ) As Double
 For i =  0  To nLen -  1 
    SD(i).Index = i
    SD(i).Value = - 1 # - i *  0 . 001 
    Sigma(i) =  3 # +  10 # ^ (-i -  1 )
 Next i
End Sub

Option Explicit

Private m_SD() As UserType
Private m_Sigma() As Double

Public Sub InitData(ByVal nLen As Long)
 ReDim m_SD( 0  To nLen -  1 ) As UserType
 ReDim m_Sigma( 0  To nLen -  1 ) As Double
End Sub

Public Sub PrintData()
 Dim i As Long
 If (Not m_SD) <> - 1 & Then
    For i = LBound(m_SD) To UBound(m_SD)
       Debug.Print "SD", i, m_SD(i).Index, m_SD(i).Value
    Next i
 End If
 If (Not m_Sigma) <> - 1 & Then
    For i = LBound(m_Sigma) To UBound(m_Sigma)
       Debug.Print "Sigma", i, m_Sigma(i)
    Next i
 End If
End Sub

Public Sub ArrJobWrapper(ByVal nLen As Long)
 ArrJob m_SD, m_Sigma, nLen
End Sub

Public Sub Test()
 Dim c As CData
 Set c = New CData
 c.InitData  3 
 c.PrintData
 Debug.Print "------"
 c.ArrJobWrapper  5 
 c.PrintData
End Sub

Test
SD              0               0               0  
SD              1               0               0  
SD              2               0               0  
Sigma           0               0  
Sigma           1               0  
Sigma           2               0  
------
SD              0               0             - 1  
SD              1               1             - 1 , 001  
SD              2               2             - 1 , 002  
SD              3               3             - 1 , 003  
SD              4               4             - 1 , 004  
Sigma           0               3 , 1  
Sigma           1               3 , 01  
Sigma           2               3 , 001  
Sigma           3               3 , 0001  
Sigma           4               3 , 00001