How to build a GtkTree?

[Guenther Meyer <d s e sordidmusic com>]

hi,

I have another problem; I did read the documentation about it but I'm a little 
bit confused about these iter/path things.

What I like to do, is building a tree from some data, that is available in  
the following format:
"catA"
"CatB"
"CatB.a"
"CatB.b"
"CatB.a.x"
"CatC"
"CatC.q"
"CatC.q.1"
"CatC.q.1.a"
"CatD"
... and so on...

I already managed to build a flat tree, but I have no clue, how to build a 
real tree out of this.