@mcmelord:
When making a variable, there's an option to make an array. The index just refers to the specific part of the array.
varriableArray[indexNumber]
@mcmelord:
Not too hard... Except for the possibility of the building itself....
First, you're going to need an 11 index point array variable, and a little initializing with it. In your initialize, you're going to take each point that you're going to have as a starting place and place it in a separate index in your array, starting at 0 for the first point, and ending at 11 for the final point. Then, in another trigger which determines where your going to start, you're going to need 3 local variables: an integer named random, an integer named i, and an integer named players. In your actions, your going to want the following:
Variable - Set players = (Number of players in (Active Players)
General - For each integer i from 0 to players with increment 1, do (Actions)
Actions
Variable - Set random = (Random integer between 0 and 11)
Unit - Create 1 Command Center for player i at point[random] using default facing (Under Construction)
That is essentially it. The Command Center can be replaced with whatever building you're intending it to be. But here is the hitch: if it's a terran building, you'll need to also create an SCV to start work immediately on it, or it won't ever complete, where as the other two races will not need a unit to do it (using standard SC2 rules.)
So... to do that, you could just add another unit create and issue a smart command on the building.... so you'd need a fourth local variable that would be a unit.... and your new action list would look like this...
Variable - Set players = (Number of players in (Active Players))
General - For each integer i from 0 to players with increment 1, do (Actions)
Actions
Variable - Set random = (Random integer between 0 and 8)
Unit - Create 1 Command Center for player i at point[random] using default facing (Under Construction)
Variable - Set building = (Last created unit)
Unit - Create 1 SCV for player i at point[random] facing 270.0 degrees (No Options)
Unit - Order (Last created unit) to (Smart Command targeting building) (Replace Existing Orders)
Anything else that confuses you, or if this isn't what you were looking for, let us know and I'm sure we'll try to help.