That’s not how RabbitMQ works. If you have two consumers consuming from the same queue, they are pushed messages basically using a round robin algorithm. It is possible to configure a consumer so that it is only pushed a maximum number of messages to consume and acknowledge (search for “consumer prefetch”), but basically RabbitMQ evenly pushes messages to all connected consumers.
Just write you application so that it opens a connection and a channel once, creates a consumer and lets it consumer forever. If you start this application twice, RabbitMQ will distribute and push the messages evenly to both consumers.