orthotropic nonlinear viscoelasticity/creep in Ansys

Hi,

 I would like to know if there is any chance to simulate orthotropic nonlinear viscoelasticity/creep of CFRP in ANSYS (e.g. by means of user programmable features (UMAT subroutines) or using the software DIGIMAT or others)? For the nonlinear part I would like to use Schapery's method.

 Many thanks for yor help!

-André