Integrating something like a budget calculator?

Hello, I'm looking to have a "Tools" page where something like a budget calculator/analyser, or rota creator...can be carried out. The output could be a display of the result of the design on the page (can be shared among selected friends)... and can also be saved/printed as a spreadsheet or word document. 
How hard would it be to implement this? Or are there existing modules that can do this?
Thanks in advance.

Any ideas?

I couldn't find anything in the market for this..  If you look on the web you can find some html and java script examples to use in a page block on your tools page.

hmm, ok. Thanks