You can't lift a horse's neck, and therefore chest, with your hands. But, to create a straight line from elbow to the bit, you can raise your hands if your horse has a naturally high head carriage.
Remember to let your horse stretch long and low a lot during his work out. Imagine if you had to run around all day with your head back in the same position! It will encourage him to seek the bit and not evade so much, because it doesn't always mean, 'be collected and work really hard.' Also, if he's in a lower level/green/out of work, don't pull his head up too high and let him stay a little above the vertical, as long as he doesn't pull.