Performance Calculation

I'm new to FileMaker, have had some experience with SQL in the past.

Because I'm the only one with programming experience at my new job (a fund manager), I was asked to create a FileMaker database to store and valuate informatione about equity titles.

I have set up a database with one table holding basic information about the titles. In a related database I store information about the daily values of each of the equity titles (values are only stored for the days that the specific exchange was active).

Now I want to calculate performances for a quick overview of the porftolio. I need to calculate things like the stock performance of the last day, the last month, the last quater or year etc.

In the title overview layout I want these numbers to be displayed. Always up to date. So I have to make a script that at any given time will look for the last value that a stock has traded at and then compares it to the value it had X days, months or years ago.

I have been trying to find a way to do this task but am having difficulties with the way FileMaker scripting works. It would be great if I could receive any kind of input regarding the solution of my poblem. Especially on the scripting part of it.

Thank you very much for your help,

Borino