Lock sections on xlsx sheet

I am looking for a freelancer to help create a system that locks specific cells on an xlsx sheet. The locked sections must be password-protected, and I want the client to be able to input their own password. I will need someone who understands the complexity of this task and can provide a secure and functioning system. The ideal freelancer will have experience working with xlsx sheets, as well as creating password-protection systems. If you feel confident in your ability to create a reliable system for me, I look forward to working with you.