  We modified the recently proposed multicanonical MC algorithm for the case of
a magnetic field driven order--order phase transition. We test this {\it
multimagnetic} Monte Carlo algorithm for the D=2 Ising model at $\beta=0.5$ and
simulate square lattices up to size $100 \times 100$. On these lattices with
periodic boundary conditions it is possible to enhance the appearance of
order-order interfaces during the simulation by many orders of magnitude as
compared to the standard Monte Carlo simulation.
