Change To Default 'copy In Same Directory' Behavior?

I'm in the habit of making a backup of files before changing them. To keep track of each version of a file, I make a copy and then rename it to include the last modified date. For example, if I'm going to edit bozo.html, I'll make a copy of the file (in the same directory) and rename it to bozo.2010.05.12.html . In Windows Explorer in Windows 7, if I right click on a file and drag and drop it in the same directory, I get a menu from which I select 'Copy here'. A copy of the file is created with the name 'bozo - Copy.html'. Is there any way to change this function to use the modified date of the file instead of ' - Copy' ?