External Task Script in Execution Listener

Hi,
I am trying to provide External js script in Execution Listener.Like below

load(‘classpath:ConstructMessage.js’)

and my whole project deploy as a war file.during run time it’s throwing following exception to me :-
ion with id ‘4d84ed6e-7f6d-11e8-b249-28d2447c697a’:TypeError: Cannot load script from classpath:ConstructMessage.js in at line number 1
at org.camunda.bpm.engine.impl.scripting.SourceExecutableScript.evaluate(SourceExecutableScript.java:67)
at org.camunda.bpm.engine.impl.scripting.ExecutableScript.execute(ExecutableScript.java:59)
at org.camunda.bpm.engine.impl.scripting.env.ScriptingEnvironment.execute(ScriptingEnvironment.java:97)
at org.camunda.bpm.engine.impl.scripting.env.ScriptingEnvironment.execute(ScriptingEnvironment.java:83)
at org.camunda.bpm.engine.impl.delegate.ScriptInvocation.invoke(ScriptInvocation.java:40)
at org.camunda.bpm.engine.impl.delegate.DelegateInvocation.proceed(DelegateInvocation.java:54)
at org.camunda.bpm.engine.impl.delegate.DefaultDelegateInterceptor.handleInvocationInContext(DefaultDelegateInterceptor.java:87)

So how can i achieve this or other way to acheive this