SQL & PL/SQL

Hi all

I am in the process of trying to reverse engineer our application in order to provide some useful documentation to others on my project. Part of it is trying to build a CRUD Matrix, so i am trying to build on the data held in USER_DEPENCENCIES and record how each oracle object interacts with a given table (CRUD).

Is anyone aware of any scripts that may give me a head start that could analyse the PL SQL code in USER_SOURCE looking for the select, insert, update, delete statements.
I know that in certain versions of toad it is possible to select a procedure/function and it can do code analysis including a CRUD Matrix, but what i am really after is a script i can run against all our code and store the results in our DB for future querying by table or by function/procedure. After much googling i can't find any code snippits that might help me get started, so any help would be much appreciated.

Cheers