dx runcommand to achieve this goal. For example, if you create a workflow called "Trio Exome Workflow - Jan 1st 2020 9:00am" in your project, you can run it from the command line in this way:
\that is needed to escape the
:in the workflow name.
dx run <workflow> --input name=stage_id:value, where stage_id is a numeric ID starting at 0. More help can be found by running the commands
dx run --helpand
dx run <workflow> --help.