Creating textfile from postgres tables

Hi,

A newby question:
I packed Cascading Stylesheets into a system of tables. i want to create
a style.css **file** out of the tables after the User updated some of
the values:

To understand what i mean better:
1.) I created 3 tables including all possible attributes/values of css
2.) I created 3 table including _some_ selected items of above (ok,
redundancie, but very effective...)
3.) i want to create a file out of 2.) like that...

create rule on update of 2.)
"make me a textfile including all data from 2.)" <<<<=== what i need

IMPORTANT: it should be able that i can add some _letters_, which do not
appear in the table (2.) (header, footer, ":","{",etc. as field
seperator)

any ideas/tips/hints

Thanks a lot

MArtin Moederndorfer