Open EXCEl sheet using PHP

[nibble290972]

I have a requirement of opening a empty excel sheet using a PHP code and making updates and publish it back to the website.

I need to follow following steps

1. User logs into a website using authentication (This works)
2. Opens a excel file
3. Updates the file
4. Saves/Publishes back into the web

Have anybody tried something similar to this.

Thanks