Tough to describe, please take a look at the test sheet.
Similar to recent post but the sheet format is much different.

If you will click the "Class row" row button then enter a 1 in the box, you will see a row inserted at the change of each class value. I have a code line that simulates adding the formulas in the data field, it puts "XX" in the first group of four columns.

Frankly I am not sure how I made that work but it is merely a start.

Each XX will need to be a formula (or the result of a formula) to add the cells above it to up to the next class break.

And to go on across the sheet to the end of the data field.

Skip a column every four columns and four more formulas. I cannot even come up with the formulas nor how to traverse the newly inserted rows with the formulas.

The formula cells need to be formatted, Bold, Top & Bottom Border, and interior colorindex 17.

The "Reset C" button puts the data back as was before rows were inserted.

https://www.dropbox.com/s/1aiz6hstvg...heet.xlsm?dl=0

Thanks,
Howard