you can do procedural generation in construct, but you can't just make a module that does that, that'd be kinda like asking them to put premade sprites in construct. the procedures that generate stuff are going to be different in every game.
that being said -
here's a quick example with beautiful art collected from actual nasa photographs[u:15zrgdzy]click here for example cap[/u:15zrgdzy]
move mouse away from center of screen to scroll, center in screen to stop
I'm not sure how much of construct you've learned, so this may or may not make sense. (i wrote this before I just changed my mind and decided to make it, took about as much time as it took to write it as to actually make it, cuz construct is cool like that) but a good start would be to make a few different basic star sprites, make them as large as the largest one you want and scale down from there. set them to not disappear when they leave the screen, and make an event at the start of layout that loops to a given number (you'll probably want to change this over and over until it looks good). for each iteration of the loop, have it create a star object, picked from the pool of stars (you can also set it so certain common looking stars have a greater chance of being picked), have it choose a random size to scale to, and make it create that star at a random location. with random brightness and angle.
this isn't in the example, but if you really want to make it look awesome you make multiple layers and make them generate random stars that are smaller on slower scrolling layers so it looks 3d, if you need some help with that it'll have to be after the easter egg hunt.
edit: as ashley said, you can save memory by creating stars as you're going along, not sure what type of game you're making and whether or not that'll ruin the effect you're going for