I am about 200 feet from the modem in our condo complex meeting room. I can pick up signal sometimes but wonder if there is a way I can hook up something to my computer to be able to boost the signal to my laptop.

I'll assume you're speaking about 802.11 wireless connectivity. You need an increase in RF reception ability not an electrical power increase. You can install an antenna with higher gain at one or both locations. A directional antenna pointed toward the modem may also work.