Loading an ApplicationContext File from AnnotationConfigWebApplicationContext

I have an application using Java config in Spring MVC. I have a WebAppInitializer and on Startup method I am using AnnotationConfigWebApplicationContext to load the rootContext.

From the Startup method of WebAppInitializer, how do I load a Client Jar that has applicationContext.xml file. Basically I am looking at something like this.

AnnotationConfigWebApplicationContext rootContext = new AnnotationConfigWebApplicationContext();
rootContext.register(MyAppContext.class);

Looking at something Like this.

rootContext.register(applicationContext.xml);