[Solved]-Shadow in Highcharts bar chart-Highcharts

You should use the Renderer which allows to add custom paths in chart. Knowing that, catch the load event and iterate on each series point, adding line in right side.

chart: {
  type: 'column',
  events: {
    load: function() {
      var chart = this,
        series = chart.series,
        each = Highcharts.each,
        r = chart.renderer,
        borderWidth  = 2,
        x,y;

      each(series, function(s, i) {
        each(s.data, function(p, j) {
                        x = p.plotX + chart.plotLeft + (p.pointWidth / 2);
                        y = p.plotY + chart.plotTop + borderWidth;

          r.path(['M', x, y, 'L', x, y + p.shapeArgs.height])
          .attr({
            zIndex: 10,
            'stroke-width': borderWidth,
            'stroke': 'gray'
          })
          .add()
        });
      });
    }
  }
},

Example: - http://jsfiddle.net/2reombm7/