The DLM_REGISTER procedure registers a Dynamically Loadable Module (DLM) in IDL that was not registered when starting IDL. This allows you to create DLMs using the MAKE_DLL procedure and register them in your current session without having to exit and restart IDL.
            Example
            Manually register and then call a routine within a DLM file that is not on !DLM_PATH:
            DLM_REGISTER, '/users/myname/mycode.dlm'
            ...
            
            MYROUTINE, a, b, c
            IDL prints:
            % Loaded DLM: MYCODE.
            Syntax
            DLM_REGISTER, File1 [, File2, ..., Filen]
            Arguments
            Filen
            The full path to the DLM module definition file to read.
            Keywords
            None.
            Version History
            
            See Also
            DLM_LOAD, !DLM_PATH environment variable, IDL_DLM_PATH preference, Dynamically Loadable Modules