You can't chnage the icon of your own .vbs script with out chnageing evey other .vbs script icon. the reason been be cause that script is assigned a icon from the vbscript Interpreter.
and if you want to know the logic of how the .vbs gets it icon look under the Registry HKEY_CLASSES_ROOT\VBSFile\DefaultIcon
you see it has a value of %SystemRoot%\System32\WScript.exe,2
WScript.exe is the Interpreter and the 2 is the icon index the .vbs file is using.
ok on the other hand if you want to have your own icon for a .vbs file and if you know how to use Visual Basic 6 I suguest haveing a look at some code I made it does what you require.
Well it allows you to assign your own custom icon to a .vbs file. I made it bcause of a scripting lanuage I was makeing here the link
Add Icons to your scripts.
Other than that I can;t think of any other way to chnage a .vbs icon. hope that helps.
When ya dreams come true.