How to access an inner jar file that resides in a outer jar?

[Gerd Wütherich]

Hi,
 
is there any possibility to access an inner jar file that resides in a
outer jar while using an ant path structure? 
 
Short example:
 
    <javac srcdir="${basedir}/source" destdir="${basedir}/classes">
      <classpath>
        <pathelement path="${basedir}/lib/outer.jar!inner.jar" />
      </classpath>
    </javac>
    
I did not find any information about it, so i would love to get further
information if this is possible and how it may works!
 
Thanks,
Gerd