In the mean time while you're looking for a course that will help... Why not try taking a deep breath letting it out slowly 3 times and say to yourself... 'My concentration is absolute. My mind is focus on this task' Often... do it 4 or 5 times a day more if you remember it. You'll notice that you do focus better on the job at hand.
Works for me and I don't mind if my concentration drifts from time to time though. Reminds me to stop an notice other things too.
Alex
