Calculator widget

Hello, I am looking for a commodity component - there are TONS of mortgage, annuity and investment calculators that do what I want. Also, the calculations for NPV are very well-known. I want to be able to embed a widget on a web page that takes a list of N cashflows and calculates the NPV of a selected subset of those cash flows projected over X period of time, eroded by an inflation rate of Y% over that same period and added to an asset initially purchased for Y and also eroded by Y% over that same X period. There needs to be a database (list of values) driving the logic of this widget, so a means of creating and maintaining that list needs to be a part of the solution (CSV upload seems appropriate, or at least a CUT&PASTE of delimited date/value pairs in the format YYYY-MM-DD,N,NNN,[login to view URL]) What I need most of all is the ability to "skin" the component, so it fits within any website with a customizable "look and feel" and a minimum of re-programming. An example of a very bare-bones interface can be found at: [login to view URL]