Create stacked Bar Chart with Linear Regression line

[BrianB]

I'm trying to create a stacked bar chart that shows a linear regression line.  I am able to create a Bar chart with 2 dimensions and 1 measure, or I am able to create a Combo Chart with 1 dimension and 2 measures (where one of the measures is the linear regression line).  However, as the Bar Chart doesn't allow 2 measures, and the Combo Chart doesn't allow 2 dimensions, I am stuck creating a Stacked Bar Chart with the Linear Regression Line.

Note that I would want to create the Linear Regression Line on the primary Dimension (not the secondary dimension).

Creating the Regression Line was not easy, but I did find this excellent guide for creating the regression line here (I used section #2): https://community.qlik.com/t5/New-to-Qlik-Sense/How-to-calculate-Linear-Trend/m-p/84332

Thanks in advance for any assistance you can provide.