NEone understand light decals?

Ok... I have to admit that I was a bit off track
with my last topic... Sorry guyz...
But I've been informed of the right terminology...
I should of been asking about lighting decals....
Can NEone give me some advice or, even better... CODE
about light decals? I really can't figure out how
to subtract from the shadows (lightmaps) and it's really
anoying.... I really need some control over light\dark
shadows n stuff... especually for my kind of style I
try to bring to games... (check out my deviantArt page
if U want to see what I'm blabbering on about:
kalisme.deviantart.com
Not thst amazing... But it's what I do)

Pleeeeeeeeeeeeeeeeez help me!
I really have to get something finished... and this
problem is like the only real one holding me back :(
I'd be forever thankful if NEone could help this
young programmer\artist\designer....

He he - I'm glad you asked because I can not figure out how the heck to do them despite Halo giving me a quick run down on the method in his ' More engine info' thread.
Anybody out there help out? I'd ask Halo but I think he's at the crunch mode stage of his engine at the moment, and will be too busy.

Anybody else? My tiny shrunken walnut of a brain simply cannot cope on its own.