Hi LoLo,
It is actually not currently possible to apply an Auctiva auto-relist profile to a listing that is already active, but that is an option we may add down the road. For the time being, in order to apply an auto-relist profile to a given listing, you must select that profile from the "Auto-Relist Profile" drop-down menu on the lister page when creating the listing through Auctiva.
Any additional questions or concerns? Please feel free to contact our customer support team using the appropriate link on our help page: http://www.auctiva.com/free-auction-software-help/help.aspx
-Mike