Possible Duplicate:
Defining a wrapper class for a set of document classes
When writing a new class (say, journal), how can I base it on an existing class (say, scrbook)?
Possible Duplicate:
Defining a wrapper class for a set of document classes
When writing a new class (say, journal), how can I base it on an existing class (say, scrbook)?
The LaTeX Companion does explain this in more detail, but here is what you basically have to do in your journal.cls:
\NeedsTeXFormat{LaTeX2e}
\ProvidesClass{journal}[2012/09/13]
\LoadClass{scrbook}
...
You need to be careful when dealing with class options. I discussed this issue when using the kvoptions key-value package in https://tex.stackexchange.com/a/68475/15616. But there are also native LaTeX commands \DeclareOption, \DeclareOption* and \ProcessOptions*.
Besides the command \LoadClass there's a command \PassOptionsToClass{<options-list>}{<class-name>} that can be used before \LoadClass{<class-name>}. This is a simple beginning of your class:
\NeedsTeXFormat{LaTeX2e}[1995/12/01]
\ProvidesClass{myclass}[2012/09/13 v0.1 My Class]
\PassOptionsToPackage{patch}{kvoptions}
\RequirePackage{kvoptions}
\DeclareBoolOption{draft}
\ProcessKeyvalOptions*
\ifmyclass@draft
\LoadClass[draft]{article}
\else
\LoadClass{article}
\fi
If you want all options user gives to myclass to be passed to article, you can used \LoadClassWithOptions{article}. However, this can have some drawbacks and I'm not sure it is always a good idea.