ExpressJS/NodeJS - Reverse Proxy Deployment

I have 3 AngularJS application each having their own ExpressJS backend. How do you deploy all 3 applications in this manner:

http://myapp.com/<app1>
http://myapp.com/<app2>
http://myapp.com/<app3>

Additional Information:
- I'm deploying the application in AWS EC2 Instance
- I tried merging the application in a single ExpressJS app. While this works, I still want to know if the case above is possible

via Michael Ardan