Depending on the names of the files, there could be many different ways to write a complicated batch file to do this.
If you are looking for a quick and dirty way to get the job done, then try what Stiddy suggested. Another way to do it would be to use attrib to mark the file as hidden before you delete all files, then unhide it afterwards.
attrib +H file.nam
del *.* /Q
attrib -H file.nam
In either case, I would probably want to add some error checking to make sure the delete command does not run if there is a problem with the copy or attrib command.