to get 27 possible combinations out of 3 numbers per positions do this

        pos.1        pos.2        pos.3

        0                1                2

        3                4                5

        6                7                8

so, you get: 012,015,018 - 042,045,048 - 072,075,078 - 312,315,318 - 342,345,348 - 372,375,378, 612,615,618 - 642,645,648 - 672,675,678 = 27 combinations

good luck!