How to hide ports and instead use routes using HAPROXY labels in marathon-lb

Question

I'm running several services on a Mesos cluster using marathon-lb to route requests to service. Currently I can hit services using routes like 1.2.3.4:1000, 1.2.3.4:2000, etc. What I'd like instead is to hide the ports and hit the services like so: 1.2.3.4/service1, 1.2.3.4/service2. I've tried using labels when setting up the configuration in the Marathon config UI. HAPROXY_0_PATH seems to be what I want (HAPROXY_0_PATH=/service1 for example, but that doesn't work. What label (or combination of labels) should be used in my case?