How to set up a PAC file for a single site in IE8?

Question

JavaScript

Good afternoon!
In a state institution, you need to set up access to the state. portal through proxy. The proxy was raised to ccproxy on a computer in the institution's network. On the proxy itself, access to any external addresses is prohibited, there is only access to the portal of the form 11.0.xx(instead of x, insert the numbers you like :)). On other PCs, there is no access to the portal, but access to the Internet is needed. If you manually register a proxy on the local machine, there is access to the portal, but there is no access to the Internet, respectively. To implement this task, I threw in the simplest PAC file, raised tinyWeb on the proxy itself and uploaded the file there. If I go through Opera, Chome, Firefox, everything works, traffic goes to the portal through a proxy, everything else is direct. But the whole problem is that this portal requires the use of ONLY IE 8, and the script does not work in either Explorer or Edge. Question how to force IE 8 to work under a script. The listing of the Pac-file is given below.

function FindProxyForURL(url, host)
{
if (shExpMatch(host,"11.0.x.x"))
return "PROXY 10.1.x.x:808";
else
return "direct";
}