Chandra,
You should be able to add lines to your chart with the ‘before render snippet.’
You’ll want to use yAxis.plotLines, like so: http://api.highcharts.com/highcharts#yAxis.plotLines
Also see: http://www.highcharts.com/stock/demo/yaxis-plotlines
There’s plenty in the community on how this looks in a skuid snippet. Here’s one sample: https://community.skuid.com/t/modify-number-formats-on-charts/1381
