Help needed with Wheightpainting

I am rigging an model for my game and wanted to know if there is a way to copy a wheightpainting from e.g. the bone of “Lip1-Left” and paste it to “Lip1-Right” in the blender version 2.49b, i tried to find some tutorials on YouTube and google but couldnt find anything helpful, someone here who knows what i have to do?

I need the wheightpaint of Lip1-Left in same size on Lip1-right

INFO: I am only using blender 2.49b for animating because im used to it and it has the OgreMeshExporter which i need for my modelfiles.