[Newbies] Matrix with Objetcs

Hi! this is the first time I use Smalltalk. I created a class called Celd and I wanted to create a class called Matrix which will be a 2D-array of Celd or a Matrix if you prefere.

Could someone help me with the code?

I tried this:

Object subclass: #Matrix instanceVariableNames: 'cells range' classVariableNames: '' poolDictionaries: '' category: 'fiuba-explorador'

initialize "Inicializa por defecto" cells := Celd new. range := 6

But when I try to add a Cell... I can't thank you very much in advance.

Gabriel