I think you want 2 different things here:
1. to start a movie with a specific audio/subtitle setting
2. change this setting on the fly while the movie is playing.
For 1, you can do that by using CDA. Make a different INI file for each
audio / subtitle setting and assign them to buttons (you can also make
submenus for buttons, so you can specify for example for one
button english soundtrack and add the submenus no subtitles/english
subtitles/german subtitles/french subtitles, etc...)
Specify bsplayer.exe as the program to run, and XXXX.INI as the parameter.
For 2, you can change audio streams and subtitles on the fly in BSPLayer!
You only have to specify the settings in the INI file.
Read my tutorial (I linked it in my earlier reply) to find out how.
BSPLayer + CDA absolutely RULE - they go along perfect together!
Cheers, Smarties :P
PS: The newest version of CDA is 2.1 but I don't know where you can
get it now that the official site is down
If you want I could post it
here (if the forum acceptsy attachments)