We don’t have any existing tools that could be used to transfer their DocuStar documents to Laserfiche.  You’ll probably need to build it yourself, or else perhaps check the Support Site Forums to see if anyone else has any experience.  I’m not familiar with the DocuStar system, but my suspicion is that converting to a briefcase will not be the optimal solution. 

Assuming the DocuStar metadata is stored in a SQL/Oracle database, you may be able to use Quick Fields or Workflow to run database lookups on import, and retrieve metadata very easily.  If that won’t work, you may want to look into creating an exporter for DocuStar that spits out an XML file with document metadata along with the file itself.  You could then build a custom importer for Laserfiche using the SDK that will automatically associate the metadata with the appropriate documents.

The feasibility of the above solutions will really depend on what’s possible with DocuStar.  I’d recommend going through the available documentation to see what options are available to you.