It looks as if the URL from your 1st entry doesn't point to an actual text file in that case, but a webpage.
If I place an actual text file on my test webserver, I do get the content.
What do you see when you open that URL in a browser and switch to "View Page Source" (or whatever your browser calls this) ?
Do you the source for a complete webpage (HTTP code) or only the names ?
If it is a webpage, then you should still be able to use a RegEx expression to filter out the hostnames.
Can you attach, in a file, the HTML code, so I can have a look.