Webcam for student to capture teacher

Hello,

I am looking for a webcam that I can connect to my laptop via usb that I can use to capture my teacher teaching. My built in webcam cannot focus in on the projector, so it just looks like a big white light, cannot see any words figures etc.. So basically need a webcam that can capture long range (20-30ft), so probably needs a zoom feature.

Could anyone recommend a webcam? I'd like it to be as small as possible as to fit in a bookbag, and inexpensive is better =)