ANT task classpath

How to set CLASSPATH for an ant task?

See below for an example  in a build.xml:

<taskdef resource="checkstyletask.properties" classpath="${lib.dir}/checkstyle-all-5.0.jar" />

       

        <taskdef name="wldeploy" classname="weblogic.ant.taskdefs.management.WLDeploy" classpath="C:\portal\ant\lib\ant.jar;E:\oracle\portal\wlserver_10.3\server\lib\weblogic.jar">