How do I create an RDP shortcut when using remote desktop connection broker?

I have 3 TS session hosts and I'd like to create an .RDP file users can just open that will connect to whichever session host is currently up and available by using a remote desktop connection broker. The goal is that if one host is overloaded or unavailable, when users click an RDP file it will automatically connect to the ones that are up. How do I create an RDP file to do this?

Here's what my environment looks like:

1. Remote Desktop Services Gateway: RDSG1.myinternaldomain.local. This server also has remote desktop web access and I've published the public URL RDS.mypublicdomain.com with a trusted 3rd party SSL certificate (there's no trusted certificate for myinternaldomain.local)
2. Remote Desktop Services Connection Broker: RDSG1.myinternaldomain.local
3. Remote Desktop Services Session hosts: RDSH1.myinternaldomain.local, RDSH2.myinternaldomain.local, RDSH3.myinternaldomain.local

Thanks!