Convert complex diagonal form to real block diagonal form with a special form (cdf2rdf)

Dear all,

I have the following question: I want to perform a similarity transformation of a real matrix with complex eigenvalues in order to achieve a real block diagonal matrix. Somehow, the command cdf2rdf can do this, however, I want that the blocks have a special form, i.e. they have a zero as its first entry.

An 2x2 example:

 A = [2 8; -1 -3];
 A_diag_real = [0 1; -2 -1]
 % with the transformation: A_diag_real = V_trans\A*V_trans

Does someone know how I find V_trans for A in R^(nxn) which yields A_diag_real where all blocks have a zero as its first entry?

Thanks!