CCTV is normally analogue, which is not compatible with PC wifi, which is digital. They have their own frequencies too, which are close to PC wifi and which is why a wireless camera setup interfere with wireless pc setups.
If the camera/s is/are IP camera/s, they are designed to be connected to a wireless router then you could use a small mobile reouter to connect to the camera and laptop, or use the laptop to connect to the router the camera/s are connected to. But you would have to crack the WEP/WPA encryption first.
You wouldnt need any software as most IP cameras have builti in web servers so you can just find the IP and use Firefox.
I have seen a number of firms and offices that use wireless IP based camera systems as they are the easiest for someone in house to setup.