excel to enterprise RIA data model?

[dzdrazil]

So, my friend has a company whose financial product runs in flash in a browser, which is designed based on a financial model specific to their industry created in excel. Currently, it relies on PHP to re-run every calculation in the application (returning roughly 25 arraycollections) based on a small amount of user input. They want to convert this to something that would run self-contained in AIR or without having to rely on PHP to perform the calculations (don't ask why it was done this way in the first place).

So, a boiled down example might be:
One table of generic variables A,B,C
One table of products (different variations) 1,2,3
One table that is performed calculations- i.e. one column user input, one column that multiplies by a generic value, and the rest are simple (value/month, value/year, etc). Each row in this final table directly corresponds to each row in the table of products.
column1: A*.5, column2: column1/.5, column3: column2*12;
Is there any decent way to do this with arraycollections? the saved user input is stored in a database, and loaded on startup, after which all the other data in the program is calculated. After each change, there are a cascade of calculations that need to be performed. My only guess is that there's a different sort of data structure that would be better suited, but I'm not from a background where these structures are often needed, unfortunately