Hi,
I am an expert in whatsapp automation and have done lot of projects similar to this.
I will create a windows application which will ask for you to login to whatsapp web and export the excel as specified with the time period input.
If interested please message me so that we can discuss further and can finish the project in few hours if given now.
If you are not comfortable with the bid , let me know your budget , so that i can see if i can do in that budget