Company Pays for items by Giving unique codes to employees

Sometimes a company wants to buy everyone a shirt or jacket. They do not want to collect individual sizing from each person. There needs to be a feature which gives each employee in a company a unique code, which discounts a specific item at 100%. In addition each unique code should only be allowed to be used once.

We should be able to enter how many unique codes we need for that specific item on that specific webstore. Then download that many codes as a CSV.