BCT15 is an analog trunktracker. You'll need a digital scanner (PRO-96/2096/106/197, PSR-500/600, Unident BCT396/996 models) to monitor Fort Jackson as it's an all-digital P25 system. You would only load the control channel for the Fort Jackson site.
LCSO is encrypted, which means there is no way to listen to them with any sort of commonly available consumer scanners or radios, digital or not. While technically possible, it would require specialized commercial equipment, in-depth technical knowledge, and a propensity to violate federal law. In short, there's no way for a common citizen to listen to LCSO without being in earshot of an officially issued LCSO radio.