I have searched all over for this

[brandonio21]

Well, you need to combine the two bits of code.. So just insert this whole block into your form:

Code:

Sub rtb_changed handles RichTextBox1.TextChanged
reLine(RichTextbox1)
End sub

Sub reLine(ByVal rtb as richtextbox)
'Where textbox1 is the textbox on the side of the TextBox1.Text = ""
Dim i As Integer = 1
Do Until TextBox1.Lines.Count = rtb.Lines.Count
TextBox1.AppendText(i.ToString + vbNewLine)
i = i + 1
Loop
End sub

And make sure that the textbox on the left is called textbox1