Help! How do I make excel display a description when I enter a product code?

Hi this is my first post and I need some help. I only have basic to moderate excel knowledge and my boss has asked me to set up a system to make our invoicing much quicker and easier.

So we create invoices in word with an embedded excel table. The excel table has headings: Quantity, Stock Code, Description, Unit Price, GST, Total, and a grand total at the bottom. I've already got the totals and gst programmed in using formulas. So all we currently have to do is manually type in the quantity, stock code, description and price and the formulas fill in the rest. But the descriptions are long and it takes ages to type em all out.

What I'm hoping to do is somehow program in all the stock codes so that as soon as you type in the stock code, it automatically enters the description and price in the next two cells. Can this be done? Can anyone point me to a resource that will teach me how to do it?

Our product list is in a separate excel spreadsheet so that may help speed things up. Hopefully I can cut and paste rather than having to type it all up coz there's like 1500 items :/

I really appreciate the help guys.

Thanks
Ric

VLOOKUP looks like its exactly what I need. I should be able to figure out the rest on my own. Thanks so much for pointing me in the right direction.