automate add to sprint board based on start date

Hello

We are working to find a better way to populate our prioritized weekly sprint board automatically. This sprint board is in our 'Design' and 'Development' space, where the project as a whole lives in our 'Clients' space. We tag specific tasks in to the corresponding sprint board when we are ready to plan out our sprints.  As you can imagine this is a time consuming process.  We typically either assign all of the tasks at the start of a project to that sprint board and leave them in a 'backlog' state or go through and assign them to that board weekly, but as you can imaging doing them all at once make the board a mess, and doing them weekly causes extra work. 

It would be great if you could add tasks to a specific location based on start date.  So if a task is scheduled to start in 2 weeks, it is added to the the sprint board based on workflow.  (We use a custom workflow for our design and development team) 

The automation feature of if task is changed from one status to another is close but still requires manual work to do that.  

Thanks