Cusolver API

Hi, I’m trying to use cusolver to solver bidiagonalization. I find cusolver support gebrd and orgbr APIs, The question is that I want to compute A = Q * B * V_T, where A is a mxn matrix, Q is the mxm orthogonal matrix, and the orgbr seems can only return a mxn orthogonal matrix Q which ensure QTQ = I_n, can I use this two APIs to compute an m dim orthogonal matrix? or can I use other functions to expand Q to a mxm orthogonal matrix?