I dont know if you can. This may work but i make no guarntees. Usually when a database is in emergancy mode, you have no other choice than to start exporting data. Ive never tried it for real. I know that doing this will take it out of emergancy mode, but im unsure if it has any affect on the database.
USE master
GO
sp_configure 'allow updates', 1
GO
RECONFIGURE WITH OVERRIDE
GO
UPDATE master..sysdatabases
SET status = 16
WHERE name = 'DatabaseName'
Stop and restart all sql server services.