It sort of depends. If you have indexes enabled (the default), and don't have an index page in that directory, you can view a directory listing just by going to http://example.com/some_directory/.
If you know the exact location of the file, you should be able to just type it into a browser (maybe email yourself the link?), or else create a web page which links to the file.
Failing any of that, install a gui front end for scp and use that. I believe there are some suggestions in kbase for that.