Short answer - no. This is where DCA is confusing - landside the ("new") terminal is split into B and C only, but airside it has three piers with separate security, south, center and north. There is a US Airways-run shuttle bus between north and center at times when US needs it for its ops. That's it as far as shuttles. The RCC should be in the center pier, and AC now operates from the south pier, so you're out of luck.

Note that AC check-in has also moved 'further south'.