you could also load up an acutal night time picture of a lightening strike into Photoshop, mask it rasterize it, copy the layer and create a new image and past
the layer into it as an transpar and then save it in a format Bryce will deal with.
Load it up do a save as so the origional layer trans is safe, and work from that angle and still have the layer if you need to start it again...
"It is not failure, I have learn 99 ways it will not work" Einstien