There's 2 file formats that can be useful, one is a .csv that usually is the Export file from within OE and the other is the native .wab file. Opening the Contacts Folder in C:\Users\USERNAME will get the
Import on the toolbar and it has the Windows Address Book for OE listed, just point to where the .wab file is stored to do it. The .csv file can be used with other E-Mail programs and as a Spreadsheet in Excel, QuattroPro, LibreOffice Calc or other such programs. Might even give OE Classic a check.