How to embed excel worksheet in a webpage

I am working on a web application and one of the features I want to add to the application is working with excel within the web app... the generic idea is basicly : there is an excel file sitting on a server and it can be displayed on the webpage.. people can edit the file and save it back to the server.. (it will have all of the functionality of Excel itself..)..

is there a way to embedd an excel file / any excel plugin exist? or maybe any alternative to excel that will give me the same functionality?

Thank you very much!