AP that can limit range

I'm looking for an access point that I could limit the range of the signal. It's for the office, and everything is wired, be we wanted a wireless box in the conference room for guests there to use (would be on a separate VLAN), but for added security, we wanted to limit the range of it as there are several other offices which would probably be in range. Another guy has used a Linksys router and some hacked software to make it work at home. Will do this if there are no other options. I searched for awhile though and was unable to find something that would do this out of the box. Any suggestions? thanks