如何在VB中读取treeview最内层的节点的值

做一个对excel自动评分（自动修改题目要求）系统
1、通过combo1查找数据库(PP.mdb有源码）的代码（自定义的函数的信息），并且单击增加评分条件按钮，把combo1内的数据赋值给评分节点的子节点
2、把treeview最内层节点值（即评分下节点的值）读取，并给它赋值给某变量或数组，
3、变量或数组通过调用自定义函数，达到评分的效果
4、给出得分情况
问题是：
2~4过程如何实现
Private Sub 增加节点__Click()
'Add a node using tvwChild
Dim oNodex As Node
Dim skey As String
Dim iIndex As Integer

On Error GoTo myerr 'if the treeview does not have a node selected
' the next line of code will return an error number 91
iIndex = TreeView1.SelectedItem.Index 'Check to see if a Node is selected

Set oNodex = TreeView1.Nodes.Add(iIndex, tvwChild, skey, Combo1.Text, 1, 2)
oNodex.EnsureVisible 'make sure the child node is visible
Exit Sub
myerr:
'Display a messge telling the user to select a node
MsgBox ("You must select a Node to do an Add Child" & vbCrLf _
& "If the TreeView is empty us Add Last to create the first node")
Exit Sub
End Sub





Private Sub 删除 _Click()
'Remove the selected Node
Dim iIndex As Integer

On Error GoTo myerr 'if the treeview does not have a node selected
' the next line of code will return an error numbe