You'll love this tip contributed by Rudi Wells!

To display attached references of a design file without having to open MicroStation, do this:

Make a copy of your MicroStation desktop icon.
Highlight the new icon, do a right click and select Properties
In the Target field, append -waref after the ustation.exe
ie: C:\Program Files\Bentley\Program\MicroStation\ustation.exe" -waref

Drag and drop a file from Windows Explorer onto the new icon.
Then press 1
Press 3 to exit.

Note, use the numbers above QWERTYUIOP on your keyboard, not those on the numberpad. Also, if you want .... you can copy the results to the system clipboard file by clicking on the little Bentley logo in the top left corner and selecting Edit > Select All and then press Enter.

This tip uses the -wa command line switch which specifies an MDL application to start when MicroStation is initialized.  In this case, the MDL is ref  which is delivered in the .../mdlsys/asneeded/ folder.

Update:  Testing on MicroStation V8i SELECTseries 3 indicates that the numerical options have been removed, but listing references still works -- see this forum post for more information and details regarding this.