We can add a DGN Link to an element. That link may refer to a file by a fully-qualified name e.g. \\MyServer\Documents\Office\Word\word.docx. It may be a relative path.

Could we use a MicroStation Configuration Variable when defining a file link? For example, suppose a project has associated Word and Excel files that live in project folder \OFFICE. The workspace configuration defines a configuration variable OFFICE_DOCUMENTS. The above DGN link might then be written $(OFFICE_DOCUMENTS)Word\word.docx.