Hi,

You need to implement this in OwnerDrawCell event of the grid. Now, to get it triggered, you need to set DrawMode property of the grid to OwnerDraw. Then use this code:

        Point pt1;
        Point pt2;

        void c1FlexGrid1_OwnerDrawCell(object sender, C1.Win.C1FlexGrid.OwnerDrawCellEventArgs e)
        {
            if (pt2 != null)
            {
                pt1 = pt2;
                if (e.Text.Contains("0″))
                {                    
                    Rectangle rect = e.Bounds;
                    pt2 = new Point(rect.Left + rect.Width / 2, rect.Top + rect.Height / 2);
                    e.Graphics.DrawLine(new Pen(Brushes.Black), pt1, pt2);                 
                }                
            }
        }

And then you get lines connecting center coordinates of cells like the screen shot.

Cheers,
Anupam.