Plesk 11.x / Windows :: Don't Have Root Access To Server As It Is A Webfusion Dedicated Server

I have Plesk 11.5 (service provider mode) on a Windows 2008 server IIS7.Most of my sites are developed in .asp and therefore i use a custom 500-100.asp error page that check s the IP of the visitor then displays either a friendly error, or if its my IP a full error of what has happened (it also emails me the error). This allows me to debug pages easily whilst developing and to keep an eye on anyone trying SQL Injection hacks on my sites (as the error and email also have session variables and IP address).I dont have root access to the server as it is a Webfusion dedicated server.I have following the Plesk documentation -

1) Switch on custom errors for the subscription
2) Look in virtual directories and navigate to error documents
3) Find the error in question (500:100) and change it to point at either a file or URL

FILE - I had the data centre add in the 500-100.asp error page in to the virtual template so that my page is available in the list of virtual files - this didn't work but that maybe because its not a static page??

URL - when i add the path it says its incorrect, if i add a fully qualified address, it accepts it but it doesn't work.give me a specific example of the URL that can be entered relative to the root as the format in the documentation isn't accepted. The last step is to restart IIS which is also an issue as i cant seem to do this from the Plesk panel..It is as if it isn't catching the 500:100 error, and only catching the general 500 error??