Importing a CATIA V4 File:
Select CATIA v4 from the File>Import submenu. The Select a CATIA v4 Model File or Export File to Import file dialog appears. Through this dialog you are able to set import options and import a CATIA v4 file.
Click the Options button. The CATIA 4 Import Options dialog appears.
Select the desired settings on this dialog and click OK.
To import a file, browse for the specific file you intend to import, click on it (so that is appears under File Name) and select OPEN.