What you need in this case is to use embedded modules.
You have to indicate to wrtc the names of the modules you need in your scripts in the "embedded modules" field. Module names must be separated by space.
Your DLL modules will be then integrated inside your exe, but still accessible as usual from your Lua scripts.
The only file needed along your exe will be the lua54.dll runtime.
See this thread [Login to see the link]