index just homepage with a cronjob (the mole is too deep)

[propain]

Hi, I've set a cronjob that reindex my site (MySql-php content), but I want to index just the links in the homepage site....
I've tried this configuation:

define('SEARCH_DEFAULT_LIMIT',0); //results per page

define('SPIDER_MAX_LIMIT',0); //max recurse levels in spider
define('RESPIDER_LIMIT',0); //recurse respider limit for update
define('LINKS_MAX_LIMIT',0); //max links per each level
define('RELINKS_LIMIT',0); //recurse links limit for an update

But my mole dig everywhere... Is there a way to do it?
I have to reindex every 1 hour beacause it is a "news" site
Tnx a lot guys!
propain