How to move a line drawn in Winforms?

Question

I know how to draw lines in a program, but I wish the user could "move that line" that he did (like a vector) to somewhere on the screen. It turns out I didn’t find anything about it at Microsoft, and maybe it doesn’t even exist.

    private Point pt1;
    private Point pt2;

    private void TelaInicial_MouseDown(object sender, MouseEventArgs e)
    {
        pt1 = e.Location;
    }

    private void TelaInicial_MouseUp(object sender, MouseEventArgs e)
    {
        pt2 = e.Location;

        // Desenha uma linha com ponta de flecha
        Pen myPen = new Pen(Color.White, 7);
        myPen.EndCap = System.Drawing.Drawing2D.LineCap.ArrowAnchor;
        Graphics g = this.CreateGraphics();
        g.DrawLine(myPen, pt1, pt2);
        g.Dispose();
        myPen.Dispose();
    }

If what was said above is impossible to accomplish using drawing tools, could anyone suggest some other way? Thank you for your attention.