This is the latest version it is possible to mine scrypt with GPU .
Start.bat if you need it !
set GPU_MAX_HEAP_SIZE 100
set GPU_USE_SYNC_OBJECTS 1
set GPU_MAX_ALLOC_PERCENT 100
set GPU_SINGLE_ALLOC_PERCENT 100
cgminer.exe --kernel scrypt -o stratum+tcp://yourpoolname:port -u your-workername -p x -T --intensity (depends on your card) --shaders 512 --thread-concurrency 8192 --lookup-gap 2 --worksize 128 --gpu-engine (depends on your card) --gpu-memclock (depends on your card) --auto-fan
pause
But as other already posted its a waste of time and energie , there are better algos for mining with GPU !