This is not tested, but until the advent of the shader nodes with P5 Materials, a pose file or light or camera - only affected the parts that the pose file addresses. For most things, the rules is: If you don't want to change it, leave it out of the pose file. If there is nothing in the file about light 1 then light 1 should stay as it is. Try this: open the light set in a text editor delete all sections about the lights you want to leave alone both the geometry calls and the actors/channels. Lights and their cameras. If the two new lights duplicate the names of lights you wish to keep, change their numbers to the next open numbers.