You don't mention what version of MicroStation you're using, so I'll assume it's a flavour of V8. Since a cell library is just a multi-model design file, you can use the tools found in the Models dialog to maintain the models in a file. Open the…

The background map requires a coordinate system to be defined for the option in the view attributes to appear. Steven's recommendation should work but if you cant define a GCS you will need to determine whats preventing the assignment

Are you not able to define a GCS because the coordinate system is unknown, goofy, or too complicated? If so, you can always define a GCS using the "Define Placemark Monument" tool on the Geographic Toolbar. All you need are at least two points that you…