.sar file cannot be included in .ear file

I need a .ear file which contains a .sar file (service archive for JBoss). Such a .sar file is declared in META-INF/jboss-app.xml of the EAR project "hska" as follows:
<jboss-app>
<security-domain>java:/jaas/hska</security-domain>
<module>
<service>hska.sar</service>
</module>
</jboss-app>

I have a "General Project" named hskaSAR which has a META-INF subdirectory for the xml files of the .sar file. Creating hskaSAR/hska.sar via the "Project Archives" view of JBoss Tools works fine. However, there is no possibility to include the .sar file within the (exploded) .ear.

I tried to edit and extend the file .settings/org.eclipse.wst.common.component within the EAR project as follows:
<dependent-module deploy-path="/" handle="module:/classpath/lib/hskaSAR/hska.sar">
<dependency-type>uses</dependency-type>
</dependent-module>

However, this workaround doesn't work.