The generator matrix

 1  0  1  1  1  1  1  1  1  1  1  1  1  1  0  1  1  1  1  1  X  1  1  1  1  1  X  1  1  1  1  1  1  1 3X  1  1  1  1  1  1  1
 0  1  1  3 5X+2  0  X  X 4X  6 5X+4  5  6  3  1 5X+1 5X+2 5X+4  5 X+3  1 X+6 5X+1 4X+2 4X+4 X+5  1 6X+1 X+6 4X+2 X+3 4X+4 X+5 3X+6  1 4X+1 5X+3 6X+2 3X+4 3X+5 3X+6 3X+3
 0  0 5X 3X 6X  X 2X 4X 3X  0 5X 4X 6X 2X 5X 4X  X 2X 3X 6X  X  X 6X  0  X 5X 4X 3X 5X 3X 5X  0 2X 4X 6X  X  0 4X 3X 6X 2X  X

generates a code of length 42 over Z7[X]/(X^2) who´s minimum homogenous weight is 243.

Homogenous weight enumerator: w(x)=1x^0+2520x^243+1260x^244+66x^245+3780x^250+1008x^251+228x^252+6048x^257+1848x^258+36x^259+6x^287+6x^294

The gray image is a linear code over GF(7) with n=294, k=5 and d=243.
This code was found by Heurico 1.16 in 0.0726 seconds.