The generator matrix

 1  1  1  1  1  1  1  1  1  1  1  1
 0  2  0  2 2a 2a 2a^2+2a+2 2a^2+2a+2 2a^2+2 2a^2+2  0  2
 0  0  2 2a^2+2 2a^2 2a^2+2a  2 2a^2 2a^2+2 2a^2+2a 2a 2a^2+2a

generates a code of length 12 over GR(64,4) who´s minimum homogenous weight is 72.

Homogenous weight enumerator: w(x)=1x^0+70x^72+252x^80+3584x^84+42x^88+147x^96

The gray image is a code over GF(8) with n=96, k=4 and d=72.
This code was found by Heurico 1.16 in 0.00186 seconds.