But how to control the mind? There are tens of techniques, from caring a beeper to write a diary every night. You need some kind of exceptions, interruptions, to catch yourself sweeping away into day-dreams and to return to the concentraction on the proper subject.
Many people will disagree, but meditation technique offers very efficient solution, like returning to posture and breathing when mind starts to wander. It is not like you must convert to Buddhism, it is about understanding how the mind works.
So, it is just a mater of a regular practicing, which will develop a new habit of observing where your mind is wandering about, so you could make any corrections.
This technique works perfectly for most of stresses, anxiety and obsessive neuroses, so it could help to concentrate on a proper subjects also.