Create library

What are the steps to build an audio plugin and use it internally in hosting code.

For example using the jucePluginDemo/ JuceDemoPlugin.lib

In host code:

#include "PluginProcessor.h"

AudioProcessor *createPlugin() {

AudioProcesor *p = new JuceDemoPluginAudioProcessor; return p;

}

How do I add this capability in Introjucer so I can use it on OSX and Windows?