the bottomline is to use a hand drill, not a powered one. You will need extreme control and a powered drill, Dremel or otherwise, is just not going to work for this kind of fine work.
The pinvise drills mentioned have a swivel head that you press upon with your index finger to provide pressure and trust me, that's all the pressure you really need.
now, back on Dremels for bit: you can buy a 3 (or 4) jaw chuck for most dremels that will allow you to use non-standard diameter tools. But don't use it for small drilling.