If you are talking about the Crossroads shopping center just at the end of Hotel Plaza Boulevard, then there is a way to get there on Disney Transport (sortof).
Take any available bus to Downtown Disney Marketplace, the cross the highway at the light (crosswalk) and take about a 10 minute walk down Hotel Plaza Boulevard.
Cross the highway at the light (crosswalk) and you are at Crossroads.
There is also a way to get a bit closer, but may not be successful.
Go to any theme park bus parking area and find the "Hotel Plaza Boulevard" bus. You can then take that bus to the hotel that is closest to Crossroads.
As stated above this MAY NOT be successful. I don't know if they check for IDs for guests staying at those hotels. I have never tried this myself.
Carol