Outlook (OL) data can be imported into Outlook Express (OE) only if both
applications are installed and running on the machine. If you're not going
to install OL on the new machine, you'll have to proceed as follows:

On the old machine, import the OL data into OE then backup the OE data.
Then on the new machine, import the OE data you backed up.

References:

Backup & Restore OE Data
http://www.insideoe.com/backup/index.htm
http://www.oehelp.com/backup.aspx

OE Files & Settings
http://www.insideoe.com/files/index.htm

OE Registry Keys
http://www.insideoe.com/files/regkeys.htm

Importing OE Data (all DBX files, including Folders.dbx)
http://www.insideoe.com/faqs/how.htm#importOE5
--
~Robear Dyer (PA Bear)
MS MVP-Windows (IE/OE, Shell/User, Security), Aumha.org VSOP, DTS-L.org

jeroen wrote:
On my old computer I am using MS Outlook (2002). On my new computer I
want to go using MS Express (6.0).

Has anybody got an idea how I can import my old messages in MS Outlook
to MS Express?

I have done some searching on the web, but could not find any solutions
though...

Thanks in advance!