Possible to create own creeper-spawners?

[FreeER]

I created a quick mod to add a second tier creeper-spawner... only now I don't know if there is (currently) a way to have the game actually spawn them in during free-play. (and yes I created a new free-play world and went out about 2500 to make sure the game wouldn't do it for me. Would have gone further but my car was destroyed by a battery of rocket turrets I hadn't seen in the dark lol)

If there isn't (which is the answer i'm actually expecting), does anyone know of a good way to script it so that when there are more than 3 creeper-spawners together they will be destroyed and the new creeper-spawner2 replace them?

creeper-danger.zip

the initial mod

(1.84 MiB) Downloaded 343 times

P.S. I noticed in my custom scenario test that the spawners can be placed on either force (player/enemy) and that the enemy forces cannot be mined...Is there a plan for the player to be able to use the creeper-spawners later on or is that for the multiplayer aspect? would be somewhat interesting to have a brain-washing research that would allow us to build a 'radio-tower' or something to convert nearby creeper-spawners to our force...or perhaps simply a genetics research to create our own slaves