Here's one way that someone managed to find
http://216.46.205.166/ubbthreads/showflat.php?Cat=&Board=SHADER&Number=387845&page=2&view=collapsed&sb=5&o=&fpart=all
It apply's it to every level block with the texture specified applied, and you have to have a wad called "standard" with the texture you want applied in it.

Hope this helped