请问如何从richtextbox中取出字符串然后替换呢？急，

[kelimacha]

已经查找到字符串的位置，不知怎么替换了，求教？

[supergreenbean]

Dim sFind As String
sFind = "ex"
With RichTextBox1
.Find sFind
.SelText = "hello"
End With