Move track up to default using a batch

[Greatestguru]

If I run this batch the default will always be Audio track 1. What can I add into this code to decide which audio track goes first.

for %%a in (*.mkv) do "C:\Program Files\mkvtoolnix\mkvpropedit" --title "%%~na" -o "fixed\%%~a" -a 1,3 -s 7 "%%~a" --forced-track "0:yes" --default-track "0:yes" --language "0:eng" "%%~na.srt"

Thanks