Hi, good questions, I think I can help
One of the basic functions built into excel, is the ability to change the formula reference ranges if you copy and paste a formula.
For example, if you put a formula in Cell C1 --> "=A1+B1" and then copy that cell and paste it into C2... it will automatically change the formula to "=A2+B2"
So thats how you can quickly duplicate the formula instead of typing it each time.
For the next question, there are already extra columns in each of the sections that are hidden by default, so you dont need to add new columns, you just need to unhide them.
You can view the video tutorials on that here:
https://mycostpro.com/video-tutorialsLastly, it sounds like you would only need 2 columns. One for the commission percentage, and then one to do all of the calculations mentioned. You dont need to do half of the calculations in one column first and then the rest in a second column... let me know if you need help with that.
The commission paid will automatically be removed from your ROI and profit as long as you choose to put it in one of the columns currently hidden in the EXPENSE or FEES group of columns.
Conversely, make sure to put the percentage of commission in one of the groups of columns that does not affect profit directly, such as the PRODUCT group of columns.
I hope that makes sense, let me know if you have any additional questions.