I wondered about that as well, so I imported it as a group, select the group node (in the Outliner or whatever) then on to Modify>Prefix Hierarchy Names, left it as prefix and then poof, the group now has 'prefix' in its name but the 'xxxx' prefix is gone from everything in the group, then you can rename the group or destroy it. If there is another way of doing this I'd like to know lol (I thought thats why the 'Search and replace' thingy was for).