Altering Hyperlinks Macro

Can anyone help. I am new to all this and have a problem that is simple to solve but I am stuck.

I have numerous worksheets with thumbnail images inserted and hyperlinked to the full size image. I need to edit all the hyperlinks at once as the file addresses have changed and I dont want to edit them manually.

I have found a code to run which works well (see below) which specifies the old folder structure and allows you to replace it with a new one.

my folder structure to the files is as follows:

c:\folder a\folder b\variable folder name\file name

How can i specify the variable folder names without having to alter it every time. The replace ment folder name will be the same for all the links. I am sure it is easy but my limited knowledge has failed me.

Sub UpdateHyperlinks()

    Const sOldPath  As String = "c:\folder a\folder b\variable folder name\"
    Const sNewPath  As String = "c:\folder a\folder b\new name\"

    Dim sNewAddress As String
    Dim hyp         As Hyperlink

    For Each hyp In ActiveSheet.Hyperlinks
        If InStr(hyp.Address, sOldPath) <> 0 Then
            sNewAddress = Replace(hyp.Address, sOldPath, sNewPath)
            hyp.Address = sNewAddress
        End If
    Next hyp

End Sub