Moving and renaming a file

 I have a folder \Logz and a folder \LogzArchive. In \Logz I have a file DailyLog.txt.
What I wanted to do is to rename the file as \Log_10/06/2009.txt and move it into \LogzArchive.
I tried the following, but the system says it does not regognise the address in the final instruction and I can't seem to find a way to make it work.
<     Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        'Put user code to initialize the page here
        '
        ' Get all the details of the previous DailyLog
        '
        Dim root1 As String = Server.MapPath("Logz")
        Dim MyOldDir As New DirectoryInfo(root1)
   ...