Design Excel macro/ program to create parent/child variations and attributes from initial list of products

Design Excel macro/ program to create parent/child variations and attributes from initial list of products. We list onto various marketplaces and use spreadsheets as the main method of uploading and changing data. Now the starting point is a title, sku, and 5 keywords. From this I need a program that will create a spreadsheet of parent child variations and various attributes. I would like the excel spreadsheet to be like a program where I can add attributes like, colours, sizes and it will automatically create a spreadsheet. The format for the spreadsheet will largely be the same so by selecting the above attributes and combining that with the starting title, description and sku etc it is possible to create product information for thousands of parent child variations easily and quickly. Image filenames and skus will follow the same logic. I have attached an example spreadsheet though there will not necessarily be so many child variations on the one I want. Accuracy is a must as is keeping to deadlines. We use macs if that makes a difference.