First create a quadratic model in med. Then you can use a simple loop like the following one:
Code:
fixed offset = 16; // your block width here
fixed x,y;
for (x = -3; x < 4; x++)
	for (y = -3; y < 4; y++)
		ent_create("yourmodel.mdl",vector(x * offset,y * offset,0),NULL);

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