Build a Web platform with Excel Online as background DB(ONLY FIRST PART)

Overview: The main goal is to actually create a web platform with Excel as the background. (The yellow colored part is the main point and will pay aud 250 for this part ) * I would like to use Excel Online in the background. * Embed spreadsheet into our web platform * When user edit on our front-end(Embedded spreadsheet), it automatically saves data to the background file. * The main Point is run macro(or something else )to "copypaste" in 20170329 Project A version 1.5 xlsm o Excel online can only handle 5MB of file so anything bigger than that will struggle. so if I use this back end process(macro), there's no limit of how big a file I can have in the back process because it runs on nornal excel(WILL PAY $150 FOR THIS PART) The reason that I want to use macro(or something else) is to copy data from one excel(this file size is below 5M and we can run it in excel online)to background excel(Above 5M and we open this using Excel Desktop software). [login to view URL](v=office.12).aspx share point will be used for this web base platform