[Typo3] kickstarter recursive relations

[Tim Wentzlau]

I am working on a extension where i need to make relations to 
tt_news_cat records.

That is not a problem thru kickstarter.

My problem is to limit the relations in the selector box so only 
tt_news_cat below the root page is visible in the selector box.
If i select the option "Selectorbox, select from root page" then i only 
see news categories that is defined in the rootpage.

I need this because i host different sites in the same installation

Tim