To help you understand the issue, try this more simple thing:
TEST.BAT
START NOTEPAD.EXE
echo all done
pause
exit
That will not do what you might expect. The command line is not the way to start windows programs unless you wish to stay in the command line.
If you wish to start a Windows program from a script, you need to use another form of script other that batch. Maybe VBScript
But if you really want to, it can be done in BATCH. But it is very awkward.
I will let somebody else explain it.