Creating PEAR Files

I have a component I have created and need to create a PEAR in order to deploy
it to some other people.  This component basically wraps a Java component.  I
want to deploy the Java component's JAR file with the PEAR so I put the JAR in
the lib directory of my UIMA component.  I have added the UIMA nature (using
eclipse) like the directions say.  When I generate the PEAR file it doesn't
include the JAR file.  I can see the JAR file in the directory using Windows
Explorer but I can't see the JAR file in the directory in Eclipse.  How do I add
a JAR file to PEAR?  Do I need to use Eclipse somehow to add the JAR to the lib
directory rather than Windows Explorer?