Build a projection simulation via Excel with MONTE CARLO

I need a forecasting tool with a Monte Carlo Simulation to show the probability of success using BOTH Excel and to create the web-code (Python) so that I can use it in a website. This needs to be automated so that the user only enters the fields in red. It will automatically generate THREE projections. ONE: Best case scenario TWO: Median (most ideal) THREE: The worst case.

PLEASE BE SURE TO KNOW STATISTICS AND ARE FAMILIAR WITH MONTE CARLO AND EXCEL!