In order to communicate with your instrument you will have to use one of the adapters in TestStand to call a code module that is interfacing with the hardware. TestStand does not have an explicit way to communicate with the cRIO in the way I think you are looking to do. You could set up an instrument driver that allows you to first get a resource handle, then pass that resource handle into other functions that allow you to perform other auxiliary functions.
Ian M.
National Instruments