I guess you are using a variable to keep your score, so then it would be:
If Score > (the certain level) - create sprite at random spawn point.
use a trigger once to make sure the sprite isn't created every tick.
sorry i was not too clear , im using the above code but can i use a or block for multiple score spawns or have to to a separate if statements , i know how i would do it in python or Java , but the process in construct 2 works its a little diff