Before I was able to write my own Paper/Velocity plugins I really needed a plugin for this and couldn't find ANYTHING despite how simple it seemed to be. So hopefully this can be useful for other people experiencing the same thing
usage
/backendservercommand:server <serverName>
for example, you could use FancyNpcs to execute /backendservercommand:server Minigames to have an npc that takes people to a server called "Minigames" (names gotta be exactly as its configured in Proxy config)
