1999 Dodge Caravan Voltage Regulator

My battery light has been coming on and recently the battery went dead. I had it checked and recharged and it happened again. I then removed the alternator and had it checked and it was fine.

I then took the car in to the auto parts place where they checked it on their equipment. I was told that it's the voltage regulator, located in the car's computer. Can that single part be replaced or must I replace the entire computer, which is more than the car itself is worth.