Multi-Series Stacked Column Combo Chart

[TMcMahon]

I am attempting to create a multi-series stacked column chart with a line. 

For each MonthYear I want to have a column for Product In and Product Out and each one stacked to show Actual and Forecast.  The line will show the Inventory level.

I have been able to create the stacked column chart utilizing 3 dimensions: MonthYear, In/Out, and Actual/Forecast.  I had one expression with nested If-Statements to create a sum for each segment of each column.  The expression also had a nested If-Statement for background color.

When I add the line for inventory level, the chart breaks. 

Due to the dynamic nature of the application, I can't create two charts and overlap with transparent background.

Any suggestions of how to create this chart would be greatly appreciated.  Thank you.