Embed, allow usage and printing but NOT download of XLS

Embed, allow usage and printing but NOT download of XLS

I want to embed a sheet in a web page and allow any visitors to fill in data and have the spreadsheet calculate the answers for the viewer and let them print the results but I do NOT want them to be able to download the XLS sheet and take my calculations and layouts with them.

The embedding went ok, and the calculations were also ok, just do not want them to get the xls.

Please point me to the correct research area.