You cant import contacts into Outlook Web Access, i just tried theres no option for it. If you have a way to setup Outlook on your computer to the exchange server then you can import then from outlook otherwise its a no go for OWA
The only way the Desktop Manager could is if you were able to make a connection with Microsoft Outlook to the exchange server, Then it could sync them to outlook. It would be nice if Outlook Web Access had the option to import contacts. Glad i could be of some help!