Using start
works for me:
@echo off
copy "C:\Remoting.config-Training" "C:\Remoting.config"
start C:\ThirdParty.exe
EDIT: Ok, looking more closely, start
seems to interpret the first parameter as the new window title if quoted. So, if you need to quote the path to your ThirdParty.exe you must supply a title string as well.
Examples:
:: Title not needed:
start C:\ThirdParty.exe
:: Title needed
start "Third Party App" "C:\Program Files\Vendor\ThirdParty.exe"