correlation two groups images with different index

I have this code that correlate between two images( group of images W22{i}) and my own template 8 images, i want pass new image(for example W22{2} to all images in my template then calculate the correlation as we shown ,but my problem when index of W22{n} is smaller 8, where 8 is number of images in template. how i can solve the problem.

     for n=1:8
    sem=corr2(template{n},W22{n});
    comp=[comp sem];

    pause(1)
end