HELP on Webinterface API Command - Need to change subtitles

    Hi


    I have a dreambox DM500HD.
    I recorded a streaming movie (.ts) and i want to play it back. However I need to change DVB subtitles (came's on a PID) during playback without showing the MENU. Is there any WEBIF API command to do it?


    I tried some commands from here http://e2devel.com/apidoc/webif/
    No success yet!



    Thanks for you help


    jh