Deploy WAR file in a external domain using Tomcat

Thanks to read me and try to help me :)

I am fighting this problem for many days ... I have a WAR file that I want to implement in an external domain using Tomcat.

I have been reading some examples like this: Similar Problem in StackOverFlow But this doesn't work for me.

I have changed the port to 80 and added this:

<Host name="www.extremadurainv.unex.es/spinav" appBase="webapps"
 unpackWARs="true" autoDeploy="true" xmlValidation="false" 
 xmlNamespaceAware="false"> 
<Alias>extremadurainv.unex.es/spinav</Alias>
</host>

But when I try to access in the webpage I have the following error:

403 Forbidden You don't have permission to access /spinav on this server.

So, do I have to change something in the Apache server? Or is it just a Tomcat problem?

Thank so much for your attention!