Not exactly sure I understand what you are asking, but the LF Briefcase is a Laserfiche export/import file format.  You export out of a LF repository into a Briefcase and then import the briefcase into any LF repository.

The LF Briefcase should not be a document inside your repository, so you would not open in the LF Client.  The LF Briefcase should be a file in a Windows folder that can be dragged and dropped or imported into the client.  This should cause the client to process and extract the data into the repository duplicating what was exported from the original source.