Can this be done? (Trying to change an image in a user form)

I was wondering if this could be done:

I have a user form with a Combo Box in the upper left hand corner and an image box in the upper right hand corner. I want to vary the image displayed in the image box based on the value selected in the combo box. Oh, and to make things even more complicated, I would like the images to be saved in the excel sheet itself instead of accessing my hard drive to look them up (because I want to be able to mail this excel sheet out to other people who won't have the images in their hard drive).

Can this be done? Sorry to be such a novice, but I am trying my best to learn this language. :-(