needing a VLOOKUP combination with something to make it work (I Think)

Hi All
I have two sheets... "X66" and the other "Master".

for each backend role in sheet "x66", column L, (L2,L3, l4, etc..)
search sheet "Master" for a match.
For "X66" B3, check "X66" B$1. If B$1 matches "Master"Sheet, column E, then fill B3="X"
otherwise, "N/A"
Repeat steps 3 and 4 for next cell until "X66" J$1
Repeat
Repeat until column L is empty

I ultimately have 15,000 to do and they all need to be added to each individual sheet based on selection. So, this would save a lot of time.
Thank you !!
Gene

excel_comparison_of_data_result.xlsx

Hi - Thank you. That is good for future use, but does not quite meet my needs. I have included a 2nd file that shows the "empty file" and the "results" of what it should look like when completed.

The existing blank columns need to remain blank, as I have other data that will go into those columns (but not relevant for this post).

Thank you for taking a look at it to give me a possible solution.

I hope someone can assist.
Thanks
Gene