How can I import all my contacts from that file?
I do not have XP with outlook express anymore...
If you don't have access to any XP computer you'll have to resort to some commercial software (e.g. Address Magic Personal, $29.95).
Cheaper but more time consuming would be setting up a virtual xp machine (e.g. with VirtualBox), import the address book and then export to CSV.
Of course there are plenty other useful scenarios where a VM comes in handy, for instance, a 'disposable' virtual computer will add greatly to your security.
If you don't have XP or a spare license, you can grab a free Internet Explorer Application Compatibility VPC Image (any of the 3 XP versions will do) and use it for with Windows Virtual PC.
If you want to import your mails, read this tutorial:
expand the link When Outlook and Outlook Express are installed on different computers