As you know, BVE4 only accepts .CSV route files but some older routes are in .RW format. Many BVE2 routes work okay in BVE4 (just without all the new features).
How to load a .RW into BVE4: 1. Download the 'BVE Route Randomizer' (BVERR) and configure it for BVE2 useage. It is available from koti.mbnet.fi/~lopomo/trainsoft/
2. Load the desired route with the desired train.
3. Load BVE4 and select BRRTemp.csv and it will load your desiredtrains and route. Next time you play BVE via BRR, it will overwite this file so you may wish to re-name it to 'RouteName.csv' or something simular.