What you will end up with:



What you will need :

Add a timer, name it : tmrWait
Add a textbox (Multi Line or not), name it : Message

Add 3 buttons :

Button1 is named : Start_Spamming
Button2 is named : Stop_Spamming
Button3 is named : cmdEnd

PHP Code:
Private Sub Start_Spamming_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Start_Spamming.Click
        tmrWait.Enabled = True
    End Sub
    Private Sub Stop_Spamming_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Stop_Spamming.Click
        tmrWait.Enabled = False
    End Sub
    Private Sub cmdEnd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdEnd.Click
        End
    End Sub
    Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles tmrWait.Tick
        SendKeys.Send(Message.Text)
        SendKeys.Send("{Enter}")
    End Sub 

Basically it will start copying and pasting the message, then click enter after each message paste...

This will be good for a person trying to program in VB.net