Hello,
I am a data analyst and R/Python programmer with good SQL/MySQL background.
I have taken the time to read your project's description and I would like to address a few points in my proposal.
Mainly, what you need here is to connect to your Mysql DSH upon the user's will and display the data, aka report it. So as long as you have the data stored in the database connecting to the database in R should be quite straight forward, but R might not be the best reporting tool out there, so it depends on what you want to report and how.
I also would like to take a look at the Excel report generator.
Thank you