associate a nt task to the end of a phase

[MedElb]

Hi all,
i'm using the antrun plugin to put a simple message or copying file at the
end of the assembly plugin,
te problem is that the message is not displayed after the assembly is done
neither the files are moved

my conf is

<build>
....

            <plugin>
                <artifactId>maven-antrun-plugin</artifactId>
                <version>1.1</version>
                <executions>
                    <execution>
                        <phase>*post-assembly*</phase>
                        <configuration>
                            <tasks>
                                <echo message="Debut de tache de déplacement
du fichier"/>
                                <copy
file="${project.build.directory}/target/distribution/*osp.${assembly.extention}"
tofile="${project.build.directory}/target/*alias.${assembly.extention}"/>
                                <delete
dir="${project.build.directory}/target/distribution/*.*" />
                                <!--
                                <copy
file="${project.build.directory}/target/*alias.${assembly.extention}"

tofile="${project.build.directory}/target/assembly"/>
                                 -->
                            </tasks>

                        </configuration>
                        <goals>
                            <goal>run</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
</build>

my question is how to associate an ant task to the end of my assembly phase
i use that maven command :

mvn assembly:assembly -Dmaven.test.skip


best regards