Modify an extensive Excel Spreadsheet

We have a very large spreadsheet that we use to import into our e-commerce system. The spreadsheet then takes all of these fields and concatenates them to create insert statements. This "script" is used to replicate products into different cities across the us. For example, You could have Widget #1 in Atlanta, Widget #2 in Detroit, etc. The project has two two pieces. The first is to modify the existing spreadsheet to account for new products. Right now the products are hard coded. We would like some input fields to accommodate new products. This will include new descriptions and images. The second part is to create a new script that can modify the existing city pages and add the new products to them and then of course load the new products. I will supply you a copy of the file, but my client is very secretive so I will have to remove the domain name and any testing will have to be done on your side. You will not have access to our servers.