Sim mechanics second generation

Hi everyone i am planning to model a single link pendulum (conventional problem) in simmechanics (second generation) my question is now i want a rotation matrix

   Rz=[cos(theta)   sin(theta) 0;...
       -sin(theta)  cos(theta) 0;...
        0              0        1];
how can i use this in simmechanics?
please help