help with matrix transformation

i am trying to take my diagnoal matrix (D) which has real and imaginary components and turn it into a Similarity matrix (C) that has exclusively real numbers, but some off-diagonal components and matrix of vectors in real-space. attached is a picture of my diagonal(D) matrix. Please help any information would be beneficial. Ultimate goal is to make it that P*C*inv(P) = my original matrix Z. attacthed is my P and Z matrix and also code as well.