I would think that getting Tomcat to run inside NetBeans would have been the hard part... If you have got that far then the help files for managing apps inside Tomcat should be sufficient to resolve this issue. I doubt there are that many Moodlers who have this configuration so you might be something of a pioneer Pinguas. I would suggest that you keep a record somewhere of what you are doing and how it works and how you got it to work. If you could, when it is all working, let me know and I will be happy to help you rewrite your records for Moodle Docs - if you would like to do that, share with others.
FYI, my record with Tomcat is patchy, it was tried by one organization I worked for but they could not get a satisfactory HTTPS-Tomcat server up and running so the idea was eventually dropped, I was supposed to get an app running, not Moodle, but could not get it to work as the server was not properly working. I did not have the time to follow it up so never bothered after the idea was shelved.