Waaaaait, you did what? Nothing in what you wrote looks like what I said you should try. You don't need to run any code, for example. You also shouldn't be entering an IP address, unless you're actually running a webserver on your phone.
If the file is called "index.htm" and is located in the phone's root directory ("\"), then you should have tried either "\index.htm" or "file://index.htm" or "file:///index.htm". These are standard ways to create a local-path URI
You could also try running a webserver, of course. The "Root Webserver" app linked in my signature will run just fine on your ROM. You'll need to make sure that it keeps running in the background (the "NoDehydrate" hack can help here, see my MultiTaskToggle app for an easy way to enable it), then run it, hit the Start button (not Back, as that would exit the webserver), load IE, and then go to 127.0.0.1. You'll need to move or copy the file to the webserver's "Content" folder, then go to 127.0.0.1/Content/index.htm.
Win8/Windows RT Projects:
List of desktop apps for hacked RT devices
XapHandler, Root Webserver, OEM Marketplace XAPs, Bookmarklets collection (Find On Page), Interop-unlock hacks.