How can we update Lead Owner while importing Leads from CSV 

I have arourd 3000 leads records, that I need to import but I m user "A" but I need that the Owner's to these Leads that are going to be imported to be User "B"
(i.e. another user from the one importing )

I m using the "Import Lead" functionlaity provided by salesforce.
Please guide me is that possible to update the CSV before importing fro the Lead Owner.. or how this can be achieved

thanks
Sunny