Oh, that's excellent! I'd written to the author of POV-tree a couple of weeks ago asking her about the greyed out obj export format and she'd said she had no plans to implement that in the future. I'd done google searches in detail to find a POV-ray to Bryce compatible format but the only one I'd come up with just wouldn't play ball. This time I've been able to get the trees into Bryce no bother. :)