The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  X  X  1  1  1  X  X  1  6  6  X  0  X
 0  6  3  0  6  3  0  6  3  0  6  3  0  6  3  6  3  0  6  0  6  3  0  6  3  0  6  6

generates a code of length 28 over Z9[X]/(X^2+3,3X) who´s minimum homogenous weight is 56.

Homogenous weight enumerator: w(x)=1x^0+66x^56+4x^57+6x^59+2x^63+2x^66

The gray image is a code over GF(3) with n=252, k=4 and d=168.
This code was found by Heurico 1.16 in 0.00444 seconds.