This can be easily achieved by using the <scope> element nested inside <dependency> element.
For example:
<dependencies>
<dependency>
<groupId>ldapjdk</groupId>
<artifactId>ldapjdk</artifactId>
<scope>system</scope>
<version>1.0</version>
<systemPath>${basedir}\src\lib\ldapjdk.jar</systemPath>
</dependency>
</dependencies>
Reference: http://www.tutorialspoint.com/maven/maven_external_dependencies.htm