Start an Orchestration if an other Orchestration gets a specific value

Question

hi
I have 2 orchestrations in one project. The second orchestration receives files which have nothing to do with the first orchestration. But I want to start the second orchestration only if a parameter from the first orchestration has a specific value. I know that you can pass values to another orchestration with the start & call orchestration shapes. But I didn`t find a way to pass a value and also receive messages which don`t depend to the first orchestration. Is there a way to do it with the start orchestration shape, or is there a better way?
thanks