BlackMagic Design's Fusion allows you to export Splines as keyframes. With this tool you can load the exported .spl file directly.

One common use case, is when you have live action footage of blinking lights, ie. police cars, or any sort of other "flicker" that you might want to duplicate the timing off in Houdini. Simply use the probe tool in fusions modifier and sample luminosity. Once you bake the spline in Fusion, simply export it as .spl and import it into houdini to drive the intensity value of a light.