Hmm.  I'm guessing that this isn't a case where "NAME" already exists in the database records?  Then, what you are going to have to do is insert it.

Create a formula, and call it something like AssignName.  It should look like:

IF {MyReport.Item_No} <= 50 THEN
    "Name 1"
ELSE
    "Name 2"

You can then create a group on @AssignName, which should break it up as you wish.