Richtextbox - find and replace

'Each time called, finds next occurence of StringToFind
Static S_Start As Long , StringToFind As String
S_Start = RichTextBox1.Find(StringToFind, S_Start)
If S_Start = - 1 Then
   MsgBox "Not found"
Else
   RichTextBox1.SetFocus
   S_Start = S_Start + Len(StringToFind)
End If