[quote user="HDR_Coder"]I would prefer to load my apps from a directory[/quote]
MS_MDLAPPS already points at a directory: \MicroStation\mdlapps. Can we assume that you mean you want to place your apps. in a different directory to the default?
MS_MDLAPPS is a multi-path variable. You can add additional paths by defining them in a configuration file. Something like this...
MS_MDLAPPS > N:/HDR_Coder/mdlapps/
Now MicroStation will look for MDL apps and DLLs in both the default directory and your own directory.