Power Query & Countif

I had a formula in a table in excel =IF([@STATUS]="",[KEY]&"_"&COUNTIF(INDEX([KEY],1):[@KEY],[@KEY]),""), which showed me how often a value showed in the data. But the same is not working in Power Query

with the formula I use to get if the same value's position in a long data list, and then I use the same in index match formula to find and locate other relevant data

I got data in number of files.. and I want create a dashboard with this data in another file which is macro enabled..

as I get the data from number of files to the dashboard, excel is making me use Power Query to link data.. once the data is linked it becomes a table and I have to add a new column with formula to get the information I need... Plus I can't add the column in raw data files, as they are just downloaded from number of different systems and want users to not worry about formula's and stuff when they get the raw data.. hope I was able to explain my dilemma.

Thanks for your help. The link did had some cool tips.

I actually changed the initial file which I was linking via Power Query.

Then I refreshed the Power Query as often I needed, that did the trick for me.