Need some help with Office Excel 2003

[Anakin Flair]

Ok, so I got this project at work. This guy wants me to make a form, complete with action buttons and drop down menus thaselect the correct information automatically. I've managed to work out pretty much everything- but the guy doesn't want me to have the drop down information in the same spreadsheet. He wants the information to update automatically from a master file. I beleive this is possible- but does anybody here know how to do it?