It’s surprisingly frustrating to add new routes to your networking configuration on OSX as the syntax is similar but slightly different from Linux. The correct format for OSX is:
sudo route -n add -net <range> <gateway> <mask>
so, for example:
sudo route -n add -net 192.168.32.0 192.168.2.1 255.255.224.0
To make sure your changes took effect print the entire routing table:
netstat -rn