Excel 2007 : Add a Spinner

Hello I am relatively new to excel. I am doing a project for a college course and have the whole project complete with the exception of adding a spinner to my worksheet and a scroll bar. For the problem I have Sales of 5,000,000 in January and they grow each month by 1%. I am supposed to insert a spinner that will enable me to easily change the sales growth each month from .5% to 1.5% in increments of .1%. I know how to display the spinner, but I cannot configure the input fields to make the spinner actually work. Any advice is greatly appreciated.

Clay