Add tip about redirecting game exectuables

content/docs/steamvr/mod-managers.md

@@ -44,3 +44,23 @@ rtex/" "/home/faith/.local/share/Steam/steamapps/common/SkyrimVR/Vortex"
 * Steam might occasionally remove the custom launch entry, just follow the guide again from Step 5.
 * You have to install mod managers and dependencies for each game separately.
 * You can't use the Nexus Mods button `Mod Manager Download` via browser, you have to download and adds mods manually.
+
+# Redirecting game executable from custom launchers
+
+It is possible to "redirect" any executable that Steam runs and launch any other executable you specify instead. This can be useful for launching Script Extender loader without having to replace any files.
+
+You need to set game's launch options to the following:
+
+```
+bash -c 'exec "${@/OriginalGame.exe/CustomLoader.exe}"' -- %command%
+```
+
+replacing `OriginalGame.exe` and `CustomLoader.exe` with game's executable name and your custom launcher respectively.
+
+Here's an example of full Fallout 4 VR launch options:
+
+```
+WINEDLLOVERRIDES="WinHTTP.dll=n,b;x3daudio1_7.dll=n,b" bash -c 'exec "${@/Fallout4VR.exe/f4sevr_loader.exe}"' -- %command% -forcesteamloader
+```
+
+Put any environment variables before `bash`, put any launch arguments for the game after `%command%`.