1) U should convert the movie into images that u can refer http://in.mathworks.com/help/matlab/examples/convert-between-image-sequences-and-video.html Then u can covert the image files into red blue and green images by accessing the index i'm assuming name of the variable that holds image file info is "RGB".
R=RGB(:,:,1);
G=RGB(:,:,2);
B=RGB(:,:,3);
Then u can refer the following link to create a new folder in matlab http://in.mathworks.com/help/matlab/ref/mkdir.html then u can use the following command to write the image file
imwrite(image,'<foldr path>','jpg')
