Sub-Object Select By Light Intensty

Hi,

I am working on o game level at this moment, modelling, texturing is finished
but the lightmaps. With a lot of polygon i have only one or two area lights. So
when i unwrap uvs with flatten mapping (spacing and angle threshold=0)in channel
3 for the lightmaps all polygons became small faces so the quality of the
lightmap is became very bad. When i export the level in the game engine the
shadows looks very pixely. To maximize the quality of the lightmap i want to
select and unwarp
 the polygons which is in the light attenuation borders or which have got some
light on the their surface. So the others can be pure black. Because of the
complextion and number of the polygons are too high i cant do this by hand. So
is there anyway to create a tool for this in max script?