You haven't explained what you have achieved so far, or what the problem is.

Anyway, here's a rough outline.

1) Download checkstyle.jar
2) Set up a checkstyle.xml file, you can just copy the sun-checks.xml
from the checkstyle distribution.
3) Define a target in your build.xml file

    <target name="checkstyle" description="Runs checkstyle on all the
source files">
        <checkstyle config="${etc.directory}/checkstyle.xml">
            <fileset dir="${source.directory}" includes="**/*.java"/>       
            <formatter type="plain"/>
        </checkstyle>
    </target>

  if you have properties called

     etc.directory which refers to the dir with checkstyle.xml in it
     source.directory where the tree containing source files to be
checked are

4) If you have the checkstyle.jar local to the project add

    <taskdef resource="checkstyletask.properties"
            classpath="${lib.directory}/checkstyle-all.jar"/>
   
    where lib.directory refers to the dir containing checkstyle.jar

  (Not sure what to do if checkstyle.jar is global)

5) Execute the target

  ant checkstyle

6) Post any error messages

James

I'd think all you need to do is put the jar in e:\apache-ant-1.6.5\lib