Indexing rich documents from websites using ExtractingRequestHandler

Hello,

I can index rich documents like pdf for instance that are on the filesystem. Can we use ExtractingRequestHandler to index files that are accessible on a website?

For example, there is a file that can be reached like so: http://www.sub.myDomain.com/files/pdfdocs/testfile.pdf

How would I go about indexing that file? I tried using the following combinations. I will put the errors in brackets:

stream.file=http://www.sub.myDomain.com/files/pdfdocs/testfile.pdf (The filename, directory name, or volume label syntax is incorrect)
stream.file=www.sub.myDomain.com/files/pdfdocs/testfile.pdf (The system cannot find the path specified)
stream.file=//www.sub.myDomain.com/files/pdfdocs/testfile.pdf (The format of the specified network name is invalid)
stream.file=sub.myDomain.com/files/pdfdocs/testfile.pdf (The system cannot find the path specified)
stream.file=//sub.myDomain.com/files/pdfdocs/testfile.pdf (The network path was not found)

I sort of understand why I get those errors. What are the alternative methods of doing this? I am guessing that the stream.file attribute doesn't support web addresses. Is there another attribute that does?