Excel has a function to change the format according to cell values and various conditions. Here is an example of a specific setting. Suppose you have a simple table like the one below, and you want to shade in red the cells where no sales have been entered. First, select the range you want to format. Next, select "Home"...

When using the sheet protection function, there is a function that allows detailed usage such as "allow selection and input in this range of cells, but not in other cells". For example, let's say you have a system that automatically creates transfer data when you enter a company name and amount of money as shown below. In this example...