Thank you, the code works best for me! I only did some minor changes: translating to origin before rotating:
Code:
euler = viz.Matrix.euler(0,0,roll)
m1 = object1.getMatrix()
m2 = object2.getMatrix()
m1.setTrans(0,0,0)
m2.setTrans(0,0,0)
diff = m1 * m2.inverse()
m2new = euler * m2
object2.setQuat(m2new.getQuat())
m1new = diff * m2new
m1new.setTrans(object1.getPosition(viz.ABS_GLOBAL))
object1.setMatrix(m1new)