Changing data in DataGridView based on existing data

Question

Hey

I'm remaking an application that my client owns (meaning that I did not create the original application), and one of requests is to simplify the data displayed in one of dataGridViews (the data is drawn from an existing database). The problem is that in the data table that this display uses, one of columns represents a type of usage of a certain product and is represented by an ordinary number. So far my client had to read from another document what does a specific number mean. Now he wants me to replace the numbers with descriptive strings (he sent me a list describing which number refers to which description), but I am not allowed to alter the database. How can I change the content of that column (in my dataGridView only, not in the database) to show the text instead of numbers?

Thanks