Neocognitron problem

My problem is regarding the neocognitron. I have read all the basic matter regarding the Neocognitron and i have to implement that in matlab. The problem I am facing is that i am not able to start writing the code in matlab. How to start and from where to start. How to declare variables and how to do calculation. How to initiate the code and how to assign the layers. how to perform calculation for the layers. I am all stuck at that.