OK. The Name is the file name so just save it and it will get a name.

if you want to do it from vba  then you would add a line after the
workbooks.add or change  the next line to

Activeworkbook.saveas FileName:="abc"

This technique is VERY useful in determining how Excel does things.
First, record a macro. ( would suggest having it stored in your Personal
workbook for now).
Then, using the standard excel menus, choose File -> Save As
Change the path to where you want to store the file, and enter the file name.
hit the return (or "save" button).
Stop recording.

Then, go to your VBA editor, select your Personal workbook  (or whereever you
told it to store it) and look at the code  for your macro.
This will give you the command syntax that Excel used to create  your file.