How do I make something like this?

[eknotix]

Hi.

I'd like to know how I can hide file paths from visitors by setting up the link to a file like this:

[a href=\"http://www.website.com/index.php?x=DOWNLOADS\" target=\"_blank\"]http://www.website.com/index.php?x=DOWNLOADS[/a]

Instead of:

[a href=\"http://www.website.com/downloads.php\" target=\"_blank\"]http://www.website.com/downloads.php[/a]

Those show web pages...I'd rather have this be for individual files...is there any way to do this?

Thanks.