I have no idea. If I were you I'd just have a bloke on the ground and put in his init field:
removeallweapons this; this addmagazine "Flare"; this addweapon "M16GrenadeLauncher"
Then in your trigger have:
flaredude fire ["M203Muzzle","Flare"]
Then you can setpos him to [0,0,0] with another trigger
This should make him fire the flare then disappear before you are close enough to see him
I suppose you could create the flare in the area using a script like:
_pointx = getpos GL1 select 0
_pointy = getpos GL1 select 1
_pointz = getpos GL1 select 2
then create the flare at position [_pointx,_pointy,_pointz+200]
Thats probably closer to what you're using now