According to the Blosxom FAQ you should be able to hide the “blosxom.cgi” portion of the url like this:

You may also be able to hide CGIs by renaming them to index.cgi, so that you can address your weblog simply by the subdirectory in which it lives, /weblog or the like. This works when the Web server has been configured to consider index.cgi a DirectoryIndex just like index.html. If this does work for you, be sure also to change $url in your newly renamed index.cgi (what used to beblosxom.cgi, setting it to the URL of your subdirectory. E.g.:

# What’s my preferred base URL for this blog (leave blank for automatic)?
my $url = “http://www.example/weblog”;

This worked fine for displaying the page, but none of the permanent links would work. I had to change the URL string to $url =”david.codebase.ca/index.cgi”. Now it works fine