Winforms: How to draw line over control without invalidating it

i have a class that draws waveforms of audio. I'm drawing it in OnPaint function. Now i need to draw a line that shows where on the waveform we are at current moment. I can calculate the position but when i try to draw it i need to call Invalidate() and that forces form to redraw all that waveform chart data (a lot of points).

So is there a way to put some transparent element over this one and then call Invalidate() only on that element? i was trying with picture box but no sucess...

//main form    
private void timer100ms_Tick(object sender, EventArgs e)
            {
                customWaveViewer1.currentPosition = (int)((stream.Position / (float)stream.Length) * customWaveViewer1.Width);
                customWaveViewer1.overlayLabel.Invalidate(false);
            }

   //drawing function in my class
   private void overlayLabelInvalidate(object sender, PaintEventArgs e)
        {
            Pen pen = new Pen(Color.FromArgb(255, 0, 0, 0));
            e.Graphics.DrawLine(pen, currentPosition, 0, currentPosition, this.Height);
        }

  //constructor
  public CustomWaveViewer()
        {
            InitializeComponent();
            this.DoubleBuffered = true;

            this.PenColor = Color.DodgerBlue;
            this.PenWidth = 1;

            overlayLabel = new PictureBox();
            overlayLabel.Size = new System.Drawing.Size(this.Width, this.Height);
            overlayLabel.Location = new Point(this.Left, this.Top);
            overlayLabel.Visible = true;
            overlayLabel.BackColor=Color.FromArgb(0,0,0,0);
            overlayLabel.Paint += new System.Windows.Forms.PaintEventHandler(this.overlayLabelInvalidate);
            Controls.Add(overlayLabel);
        }