[TYPO3] writing a hook for starttime and endtime

[Praveen Chakravadhanula]

hey hi i am working on a news site. what we are trying to do is grant a one
day approval when the customers apply for subscription. this one day grant
should expire after 24 hrs from the time they logged in at the time of
registering as a new user.

i am using the frontend user resigration extension, and some hooks are
available there in the extensions. i know we have to write a hook and i
also have  a simple php code for it . it goes like this
           
              'starttime' => time() // gets the current time// for example
display ( 04-21-2007)
              'endtime' => time()+(1*24*60*60) // get the next day//
displays (04-22-2007)

and i wanted to include this code in a hook called
confirmbeforeregistration , this is already
there in the extension under tx_srfeuserregister_hookhandler.php.

by problem is how to include this code into the given hook. i have never
done it before and having problems in writing to the class.

can any one please help me out. i am stuck here. i really appreciate it.
thank you in advance 
praveen