Because of this method of linking, Windows has to be able to find and load the DLL file. To be accessible, the DLL has to be placed either in the path where the calling application is, the directory of Windows or its system path, or in any path contained in the system search path.
The same is valid for the DLLs List & Label uses.
These DLLs must be copied into a path in which your program is installed, or which complies with the requirements stated above.
The List & Label DLL and its dependent DLLs can be installed for Side-By-Side use in your application's directory.
See chapter Redistribution: Shipping the Application for further information.