Kawecki has a dynamic hair convertor in freestuff. It will open a saved dynamic hair library (HR2) file and "expand" it into a full OBJ mesh - although that makes it bigger of course.

It also has an option to open an OBJ. I'm not sure why that's there, if there's no way of getting a dynamic hair in OBJ form - I thought the hairs were represented as lines? Maybe Kawecki knows something we don't. :)