I think I get your point, but you don't listen mine.
But I've said something wrong previously so here is another explanation :
I open the remote editor and choose File > New. I then get a blank file which mIRC names as script(#).ini.
I don't want it named script3.ini so I choose File > Save As and name it what I like. What happens then is mirc saves two files.
When creating a new file, mirc isn't saving the file on the disk in case you click cancel, so it's only saving the file when clicking Ok.
What you described is before mirc store his file, you're saving it under a name, this is the first file you're talking about.
After clicking ok, mIRC then store the file under the name he choose, here is the second.
If this is true then you are using "mIRC" incorrectly, if you don't want the second file, let mirc store his file first and rename this file.