Executable should have a property async launch

I have a step in my install.xml izpack file that launches a windows batch file that starts a job (exe) that does not go to background (postgres start database pg_ctl.exe) when it completes so the terminal windows is left hanging waiting for a CTRL+C to stop the DB.

I would like to have an option that allows executable files to be launched in izpack but continues after launching so it does not wait for completion (async like)