Not sure what you are asking, but if you want a stored procedure to start multiple packages so they all run at the same time, then the easiest way is to create a job for each package. Then, in your procedure you can start the jobs - which will then run concurrently.
I would recommend upgrading to SSIS and rebuilding the packages. With SSIS you can control that much more effectively in the package itself, instead of relying on SQL Server.