If you're able to synch this account to a mail server that has your contacts stored, you can easily plug your iPhone to your computer with your Apple Cable. Then in iTunes select your iPhone from the left hand column and go to the Info tab. You can scroll down and select your Contact synch settings.
As you have a Windows XP, your Outlook contacts should already by loaded in your Windows Address Book. You only need iTunes to import contacts to iPhone from your Windows Address Book.
Simply connect your iPhone to your PC and run iTunes. Next, navigate to the Info tab from the iPhone settings in iTunes and tick the "Sync Contacts with" options. From the drop-down menu, select Outlook or Windows Address Book - depending on where your contact entires are saved on your PC.
This is it: now click on the Sync button and your Outlook contacts will be loaded to your iPhone.