Don't use it. Halogen lights are a type of incandecent light and incandecent lights are crap for growing plants. Stick to flouros or HID lights. Those are the tried and true lights to use.
Honestly you can grow a plant with halogen (veg). It grows a weak plant belive me. But its not worth it, theres too too too much heat comming from it and it dosn't have the correct spectrum. I grow this 4-1/2 foot plant with a 500 watt halogen work light. [img=http://img89.imageshack.us/img89/8016/qwen.th.jpg]