Is it possible?
What's the "homepage" for you? Do you mean the index page? If yes, then use anycontent.php and add a PHP-driven toggle there that checks the variable $cat. If $cat == 0 then display the special content, otherwise not.
if ($cat == 0) {
"content"
}
Don't seems to work :(
Doesn't work where? What error message do you get (except for the obvious parse error, as the code you posted will of course not work because it isn't valid). It depends where you want to use that piece of code. Post full examples of what you did. Posting a link to your testbed might be a good idea as well.