add a 'killed' event handler to the object to sense when it's 'dead'. make it something like this:
object_name addeventhandler ["killed","{[_this] exec "instant_respawn.sqs"}]
then copy/paste this:
;instant respawn
_what = _this select 0
_x = getpos _what select 0
_y = getpos _what select 1
_obj = "object" camcreate [_x,_y]
exit
save that as "instant_respawn.sqs".
that should work, assuming you know the camcreate 'name' of the static object you're trying to respawn.