changing DOM Implementation - compileoptions with ant?

Hi XMLC-Professionals,

can anybody tell me how xmlc compile-options
can be used with ant?
I am using following target:
<target name="xmlc" depends="prepare" description="generate java source files from html templates">
        <echo message="xml compiling"/>
        <xmlc srcdir="sources/web"
              destdir="${build.classes}"
              includes="**/*.htm*"
              sourceout="${prebuild.dir}/src"/>
              <!--verbose="true"/-->
</target>
how can I change the dom implementation from lazydom to Xerces?

thank you all for help!
Florian