Project- text files help

Question

I am required to develop a POS system using C# for a small shop which sells items like bread,milk etc... the part that i don't get is this. "The system must first store those items on a text file as follows[item Code,Description,Price] where :

Item Code is 6 characters long. First 3 letters of the item and a 3 digit number e.g Bre123.
Description _ e.g Bread
Price of item

When doing a sale the system must read that particular item code from the file and display it on screen.

All help appreciated.