You live in Germany?
BR 101 is used more often for freight trains in the past. It has build as universal locomotive (passenger/freight trains) between 1996 and 1999. But it's right, the main scope of duties were directly the express passenger services because these locomotives had to replace the time-worn German class 103 locomotives.
But from time to time you could see a class 101 hauling a freight train (not only in the present):
BR 101 026 at Mühlacker 01.08.1998 [bahnbilder.de]:
http://www.bahnbilder.de/bilder/br-101-244343.jpg
BR 101 065 at Tamm 13.03.1999 [bahnbilder.de]:
http://www.bahnbilder.de/bilder/br-101-244345.jpg
BR 101 013 at Geislingen-West 17.07.1999 [bahnbilder.de]:
http://www.bahnbilder.de/bilder/br-101-244336.jpg
BR 101 022 at Amstetten 27.04.2004 [bahnbilder.de]:
http://www.bahnbilder.de/bilder/br-101-244340.jpg
There are many more pictures in the worldwideweb where you can see the German class 101 in front of a freight train. So it's nothing new and you can set up such a scenario for RailWorks in the time from 1996 (perhaps better 1997 - first rollout was in summer 1996) until the present time.
In the future this class will be used more often for freight tasks because the engine is still good at work and many express trains will/should be replaced by multiple units in the near future.
So, now we can actually use them - in game!
Why not using this engine for express passenger services - the main task of this engine and you have the needed coaches directly in your RW folder.