Export an animation from unity at a fixed frame rate.

I'm using some assets and unity features (physics, AI, etc) to create an animation in a scene. That animation will be rendered with other software (3ds, cinema 4d), so I need to export that animation, and I need to export it at an specific framerate (24, 25, 30, 60, 120...) even when my hardware can only render 20 fps in real time.

So what I need to do is, for example: If I need to get a 30fps animation, make sure that each frame is calculated in unity 0.03 seconds in advance respect to the previous frame. Although this frame will take to unity 0.1 seconds or 2 seconds to render.

Does anyone know the best way to do this? Thanks