Simultaneous RDP sessions

I am trying to setup controller to be able to open multiple simultaneous RDP sessions from the same server.
Each agent is on a different login.
Every time it is trying to start/stop any agent, it will login with the same ID.
How can logins be assigned according to agent.
Workflows are all GUI and need to capture images.
Appreciate any suggestions. Wouldn’t like to have a different controller for each agent. That would be unproductive and financially not very atractive.