During my session at MACC I could not remember the correct name of the vba search directory config variable. And, I forgot to include it in my notes, but here it is in Bentley Systems MicroStation VBA Help.

The MicroStation configuration variable MS_VBASEARCHDIRECTORIES determines the directories in which MicroStation will search for projects when they are loaded by name. This variable also sets the location from which VBA projects can be autoloaded at startup time. 

You can also Auto-load specific MVBAs using the AUTO Loader variabl MS_VBAAUTOLOADPROJECTS. This is the variable that is set when you check the Auto-load column in the Project Manager dialog. An MVBA defined by this variable does not need to reside in a vba search directory.