Is anyone here familiar with the cutscene SEXP's ? I created a creditmission (mostly so that I can play the campaign outro correctly), but those SEXP still give me a headache. I tried many cool ideas (in my opinion

) but I always failed creating the entire mission because at one point the SEXP didn't worked anymore (i.e. the fade-in fade out stuff stopped working after a camera move

) However, I'm confident that they will be fixed sooner or later, if they haven't been already

My current question is this:
I created that creditmission and display only subtitles with that SEXP. They look like this :
-true
--show-subtile
----425
----420
----text
----4500
I used the trial/error method to find a more or less central position of the screen using 1024x768. But now when playing in 1280x1024 of course everything is out of place. But the SEXP-Explanation tells about more values,
and No. 7 is "center horizontally".
But how can I enter value 7, when I don't need/have to enter value 5 "image name" and value 6 "fade in time".
Can anyone tell me how to use/insert the "center"-values ?