This simple JS conversion takes the output from Outlook Express's "Export Contacts" text file and turns them into a vCard format, so that you can import all your Outlook Express contacts into the Address Book application for OS X.
If you have troubles with this, perhaps the more generic CSV to vCard tool will help. (Then again, perhaps not.)
It has been shown to me that Apple does include an applescript for going from various MacOS 9 programs to the Address Book. While it doesn't solve the general case that CSVtoVcard solves, if you have OE, you really should just run the apple script installed on OS X at/Library/Scripts/Mail Scripts/Import Addresses.scpt
Its description states:
This script is intended for users wishing to import their addresses from Entourage, Outlook Express, Eudora, or Palm Desktop into Mail.
The Entourage and Outlook Express importers have the option of importing directly from the application (if you have it on your computer) or importing a text file that has been exported from either of these applications. If you choose the direct import option, more of your data (like groups and categories) will be preserved.