The import file includes what the old domain was an attempts to import (download) the media items.
Also, if you are just moving to another hosting account, you should be moving the full db, all files...Please call GD, tell them you were given poor advice, and tell them (be persistent) to grab you old db and files and put at new hosting account...
It did not and should not have required you to import this file. The whole site should have been migrated.
