Pricing Grid

I am trying create a pricing grid on excel 2003. I have a small pvcu window business and I need to give a pricing grid to my customers for quick calculation of a window price. It would have the window widths in increments across the top and the height increments down the side. It would have approx. 10 increments each way. I would like to be able to put known price values in each corner and have excel fill in the rest. Is there any simple way to do this as I am not brilliant on excel.
I look forward to your help.