Trend lines- Line chart

Your sample file is quite large and slow, so I did not spend much time with it.
Your sample picture in the docx file suggests a simple column chart, with a horizontal line added and a trendline added.
I assume you already know how to create a column chart.
One of these techniques can be used for adding the horizontal line: http://peltiertech.com/Excel/Charts/AddLine.html
Getting the trendline should be as easy as executing the "insert trendline" command (2007 help file: https://support.office.com/en-us/art...1-3c6e4b5c5812 most other versions should be similar. search the help file for your version, if the instructions here are not applicable).