Trains arrive at Belarus Station from Belarus (Minsk and Brest), Kaliningrad, Smolensk and international destinations including Vilnius, Warsaw, and Berlin. The station is around 20 km north of the Eridan Hotel.
By taxi
It should not take more than 40 minutes to drive to the Eridan Hotel except in the worst rush hour traffic. If you can negotiate a taxi on arrival, the fare should be around $40, but it is probably easier to arrange a transfer with a driver to meet your train, which you can do here.
By metro
Take the metro from Belorusskaya Metro Station, and travel south on the dark-green line two stops south to Tverskaya. Change there to the gray line from Chekhovskaya, and continue south nine stops to Chertanovskaya, which is around seven minutes' walk from the Eridan Hotel.