【求教】WebBrowser打开一张网页时，怎么替换指定字符

【求教】WebBrowser打开一张网页时，如何替换指定字符
比如我用WebBrowser打开http://www.baid.com，我想把 "关于百度 "换成 "关于我们 "

------解决方案--------------------
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
WebBrowser1.Navigate( "http://www.baidu.com ")
End Sub
Private Sub WebBrowser1_DocumentCompleted(ByVal sender As System.Object, ByVal e As System.Windows.Forms.WebBrowserDocumentCompletedEventArgs) Handles WebBrowser1.DocumentCompleted
Dim vDocument As mshtml.IHTMLDocument2 = WebBrowser1.Document.DomDocument
Dim vBody As mshtml.IHTMLBodyElement = vDocument.body
Dim vTxtRange As mshtml.IHTMLTxtRange = vBody.createTextRange
If vTxtRange.findText( "关于百度 ") Then
vTxtRange.select()
vTxtRange.pasteHTML( " <a href= " "http://blog.sina.com.cn/zswang " " target= " "_blank " "> <b> Zswang </b> 路过 </a> ")
End If
End Sub