RDS 2012 two Gateway

I have RDS 2012 Setup with Two gateways in DNS RR and 2 Session Hosts and all woks fine

GW1 -  Gateway 1

GW2 – Gateway 2

RDSH1 – Session Host 1

RDSH2 – Session Host 2

Connection Broker in HA

I need the Below to be setup

All Application hosted on RDSH1 should go via GW1 ( Gateway 1 )

And

All Application hosted on RDSH2 should go via GW2 ( Gateway 2 )