Veriloga might be the way to go. But when you say R(t)
and V(t-1), I think about the difference between
simulation time and simulation timestep; are you going
to sample and set, or make this a continuous function,
and so on. Do you need to "remember", to react at a
fixed time lag, to continuously change with zero delay?
These are for you to think about. If you can express
it, I'm fairly optimistic that you can code it. But clarity
is a key stepping-stone, to that.