Create a pareto chart with % line starting from top point of first data point

I have no problem creating a pareto chart, but what I can't seem to understand is how to make the line start from the top of the first data point? I've seen this done before, but not idea how to make it happen.

In the case of the attached example, the line would start at the top of the Jan data point.

Debra Dalgleish has my automated pareto plotter at her Contextures website:
http://www.contextures.com/excelfilesRon.html#RF00010

See if that helps.

Thanks for the link Ron.

It seems I've looked at this from every angle but my mind can't wrap around how you set the line to the top right corner of the first bar and the top right of the chart!

Can you give me some pointers of what to look for?