Hi Andy, no there isn't any way that I know of to export curves to Modo.

I don't believe that Modo actually has NURBS curve entities inside of it? The last time I checked it used some different kind of spline curve (not NURBS) for paths and stuff like that.

But another approach that you could use would be to take a screenshot of MoI and then composite that with the rendering. PaQ has done that a few times and I set up a script for him so that the camera view in MoI could be matched with the one in Modo, see this previous thread:
http://moi3d.com/forum/index.php?webtag=MOI&msg=3644.1

- Michael