Hi, there!
My name is Paris, and I was glad to see that you're looking for an Excel developer. According to your brief, you want to have an Excel sheet checked for duplicates and add some data if a duplicate is found. I will send you the output file. For an extra milestone, I could develop a macro that will repeat these steps for a different set of data. this way you could replicate the desired set of steps in the future. I will charge you $100 and can deliver within a couple of days (a single milestone to release once you're satisfied with the final result).
I'm among the most experienced and skilled Excel, and VBA developers on this platform. I am in the top 3% of the freelancers having completed over 300 projects successfully in six years, and I feel confident in achieving your task as well. You're welcome to visit my page (https://www.freelancer.com/u/paris2785) and get an idea of who I am and what services I provide to my clients.
I'm online from 8 am to 9 pm, Athens time (including weekends).
I'm looking forward to working with you.
Sincerely,
Paris Pallas