I assume that you use the maven-antrun-plugin because this snippet looks more like an ant script.
As described in this answer you can pass maven properties to the maven-antrun-plugin:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-antrun-plugin</artifactId>
<version>1.7</version>
<executions>
<execution>
<id>compile</id>
<phase>compile</phase>
<configuration>
<target>
<property name="antProperty" value="${my.custom.property}"/>
<echo message="Custom Ant Property is: ${antProperty}"/>
<echoproperties />
</target>
</configuration>
<goals>
<goal>run</goal>
</goals>
</execution>
</executions>
</plugin>
You can now pass the property value via command line to the maven build:
mvn compile -Dmy.custom.property=hello