[development] How do I write to the database?

[AustinCMS]

My colleague is trying to simply write to a mysql database. And having
a pretty difficult time of it.
He has gone through the forums, posts, books and Pro Dev Drupal and is
still having
a problem

We are wondering if it is because he are working with computed fields?
Does that make any difference
in syntax, for example?

If someone could post any samples they have used of syntax - writing
to a Drupal 6.15, standard install using
computed field values - we would be so grateful. If it works, send me
your address - and I'll send you
a $100.00 bucks in pure gratitude!

Kind regards,

Chana