From that description, the camera is ' phantom powered '. This is quite common to save on cabling. The DC supply goes up the coax, normally + to the centre core, and - to the braid. It is injected via a small choke to isolate the low output impedance of the supply, from the high frequency video. The video signal appears superimposed on the DC. A simple capacitor in series with the coax centre, will remove the DC component, but depending on the configuration of the input circuit on the device that you are going to feed into, the signal may need to be re-clamped first. The capacitor value should be fairly large, say 2u2 25v working, with its + terminal facing into the coax from the camera. The other socket will be a standard configuration for an auto iris lens.
I have the TK-S100 which sounds similar but has an extra 'phono' style jack. On mine the BNC (labelled CCU) attached to some sort of control unit, from which it derived its power, and the phono is the video output. To attach your camera to a PC you'll need to buy a video card with 'VIVO' (video in, video out- ie a capture card) or a TV card with video in, and buy a lead to interconnect them. Probably a phono to phono (as that is what capture cards tend to use) and a BNC to phono adapter to fit onto the camera, unless you can find a cheap source of BNC to phono leads.
However, if this camera has no conventional power input, things get very much more tricky. I assume the DC is carried along the video cable, so unless you are electronically-minded you'll find it impossible to get it working without the proper bits to do the job.