The following function will create or append members (or existing distribution lists) to a named distribution List. You can call it as many times as you have entries in your worksheet.
Using the format "Name (e-mail address)" for individual members or just the name for the list.

CreateDistributionList "ListName", "Name (e-mail address)" 'member
CreateDistributionList "ListName", "ListToAppend" 'list


Private Sub CreateDistributionList(strListName As String, strMember As String)
'Graham Mayor - http://www.gmayor.com - 28/09/2016
'strMember should be in the format "Name (e-mail address)"
'or Distribution list name
Dim olNS As Outlook.NameSpace
Dim olFolder As Outlook.Folder
Dim olDistList As Outlook.DistListItem
Dim olFolderItems As Outlook.Items
Dim objRcpnt As Outlook.Recipient
Dim x As Integer
Dim y As Integer
Dim iCount As Integer
Dim bList As Boolean
Dim bMember As Boolean

    Set olNS = GetNamespace("MAPI")
    Set olFolder = olNS.GetDefaultFolder(olFolderContacts)
    Set olFolderItems = olFolder.Items
    bList = False
    bMember = False
    iCount = olFolderItems.Count
    For x = 1 To iCount
        If TypeName(olFolderItems.Item(x)) = "DistListItem" Then
            Set olDistList = olFolderItems.Item(x)
            'Check if the distribution list exists
            If olDistList.DLName = strListName Then
                bList = True
                For y = 1 To olDistList.MemberCount
                    'Check if the member exists
                    If InStr(1, olDistList.GetMember(y).Name, strMember) Then
                        bMember = True
                        Exit For
                    End If
                Next y
            End If
        End If
    Next x
    'If the distribution list doesn't exist - add it
    If Not bList Then
        Set olDistList = CreateItem(olDistributionListItem)
        olDistList.DLName = strListName
    End If
    'If the member doesn't exist add it
    If Not bMember Then
        Set objRcpnt = olNS.CreateRecipient(strMember)
        objRcpnt.Resolve
        olDistList.AddMember objRcpnt
    End If
    'Save the change to the list
    olDistList.Save
lbl_Exit:
    Set olNS = Nothing
    Set olFolder = Nothing
    Set olDistList = Nothing
    Set olFolderItems = Nothing
    Set objRcpnt = Nothing
    Exit Sub
End Sub