Well I am not even near to it
And this is not very conforting :
www.limesurvey.org/fr/forum/can-i-do-thi...limesurvey-responses


all rite it's not that funny but it means that this is wanted for years !
Serioulsly where is the guy who wrote this huge exportsresult.php ?
Don't you think it would take so many time for this guru to provide a simple script to get csv ?

Let's be constructive maybe some others will have the will and with the will we can everythings...yes we can !

foreach($_POST as $key=>$value)
{
echo $key."=".$value."&";
}
gives us
export_from=1&export_to=3&filterinc=show&exportstyle=headcodes&answers=short&convertyto=1&convertnto=2&type=csv&sid=63226&answerid=3&colselect=Array&checksessionbypost=vutv73gwdq

so wee need all those parameters to get our csv but we can't run the script from outside the admin.php or else we get a warning on csrf token violation

If I just take the script outside and comment the line...ahem ^_^

When I look again to that function my arms are falling down on the floor...How come this two csv lines are so complex to produce ???

For Limesurvey 2.0 we are porting all code to the MVC framework "Yii". I'm not sure if thise file was already properly restructured but you can check out the "limesurvey_yii" branch to have a look and test.
For the upcoming Google Summer of Code (if we will be accepted again by Google this year), there might be a task to create an API for such cases, see docs.limesurvey.org/Project+Ideas+for+GSoC+2012