get combined textbox text into a new one in sorted checkedbox order

Hi, I have a question, how can I achieve this, like I have declared 3 variable as string, each checkbox has a variable that will be created if clicked also when checked it will put the corresponding textbox.text into it. Now the problem is I need to make sure that the first one that will be selected will be the first one that will be paste thanks to the variable, the seond checked and third checked same thing. This is the code

 Private Sub CheckBox2_CheckedChanged(sender As Object, e As EventArgs) Handles CheckBox2.CheckedChanged
        Dim fntext As String
        Dim artext As String
        Dim dltext As String
        If CheckBox3.Checked = True Then
            fntext = TextBox1.Text
        ElseIf CheckBox4.Checked Then
            artext = TextBox4.Text
        ElseIf CheckBox5.Checked Then
            dltext = TextBox6.Text
        End If
    End Sub
    TextBox7.Text += fntext & vbCrLf & artext & vbCrLf & dltext
End Class