I was digging through the WoW API today, and noticed the RunScript("script") command. I thought perhaps this command could be run, the "script" could be taken from an incomeing whisper, effectively setting up a remote connection.
I'm debateing how usefull this could actually be, and also how you would secure it. You wouldn't want it to accept a whispered command from any person. The core function of the mod would be fairly simple to design.
local name -- this variable would be the name of the person you want to give script access to. Set via a slash command.
if arg2 == name then --check to see if the whisper is from the person we are giveing access to
RunScript(arg1) -- execute the whisper as a script function.
I suppose it would make sense to take arg1 and check to see if it started with something like "!!script SomeMod:SomeFunction(args)", then filter off the !!script and pass the rest onto the RunScript command.