adding classes of a jar file to another jar file (especially ejb-jar file)

Hi
In JBuilder X it is possible to add whole classes of a Jar file to another jar file,
this is a feature which is required for working with EJB-JAR files, for example it must be possible to add log4j.jar to a EJB-JAR file,

is it possible to do the same work in IntelliJ 4?