Hot to code industry in copy paste way?

[Kogut]

I discovered cargo challenge for locomotion: http://www.tt-forums.net/viewtopic.php?f=39&t=11170 (thanks to grave digger!).
I like it, and I decided to create sth similar for openttt (as industry set).
Unfortunatelly I failed to find any tutorial about coding industries.

I want only to create one raw industry (producing cargo 1). (Or use existing Iron Ore mine)
And secondary industry (cargo 1 -> cargo 2).
And tertiary industry (cargo 2 -> cargo 3).
And so on.

So I need informations how to code newcargos and modify steel mill.