Configure a computer for 2 Default Gateways

In the scenario where I need a computer to have 2 Default Gateways , how should I  configure the computer to achieve this goal.
I know that there is Route Add command in windows that can add a second DG to the computer. However in large environment, is Adding Route to computers is done manually or through a script or it is a configuration done through a router ?

in the topology below, assuming computer C1 is configure with DG of R1 interface but it  also needs to reach Network 192.168.10.0.

How is this done ?

Thank you