Cable Line/Coax Question?

Don't think i am asking how to steal cable. but i just got a PROSCAN HDTV. i have Charter's HD Service and i am not very confident of the quality of the coax/cable line in my particular apartment. there is a cable (center?) or a box where my complex all connects to.( once again, i pay for Charters(R) Cable Service and I am not asking how steal cable. ) i was just wondering where/how i could run a higher quality line from that box(or center?) to the room with the HDTV. any info would be great1! -- Thanks