I am developing a web based application that requires extensive works on spreadsheets. The spreadsheets are already created and are updated on daily basis. I just want to open/embed the MS Excel 2003/2007/2010 Application inside my web page. It should seem like the application is running inside an Iframe.
Users can click on file name. It will open the ms excel exe file inside iframe, they'll use the spreadsheets just like using it when ms excel is opened inside desktop.
If you're budget allows for it i would recommend not to re-invent the wheel and use a third-party component like Aspose Cells which comes with ready-to-use Excel spreadsheet visualization and manipulation controls. Check out the GridWeb.
Of course there are a lot of other vendors selling similar components with asp.net controls too.
If you have more time than money you could use a free asp.net grid control like RealWorld.Grid or a platform independent solution like dhtmlxGrid (which is only free if your project can be GPL'd). This of course will leave you with a lot of footwork with the office interop libraries.