I've done a lot of excel work like this.

You'll need to be good at excel and eventually excel vba...and have a programmer's mentality. Everyone doesn't have it.

You'll also have to properly define your candle sticks. All hammers aren't of the same proportion nor size, etc. Some proportions may work better than others. How will you know.

Which parameters will you use for the other indicators. Are you going to assume the standard parameters are best, or are you going to code additional programs to backtest them individually to see how they perform.

How will you recognize and deal with curve-fitting.