How to add a Goal to a Summary Report

We want to create a report that has a bar chart of Sales by Employee by month and show the goal for that employee/month, perhaps with a line.

The goal comes from an EmployeeGoal table where the goal will vary by employee and by month.  This allows for seasonal variation of sales and goals.

I am thinking this will require a HighCharts javascript solution, but any other ideas on how to do this are appreciated.  If ETL is required, it has to be automated.

Thanks,
Dean