Ah, OK. It's not a "Copy Script" -- it's a shell script.
Place set_icon in your Home folder instead, and make sure that when you look at it in Finder, its "icon" is a Unix Executable. Then, fix your "after copy" shell script choice in options.
The icon looks just about right, as long as you're logged in as "parents" when you run.
That should fix it, I hope. And thanks for taking the time to get in touch and for your english -- believe me, it's far better than my terrible french.
"De rien"
