Yay! Got it!
Another lame extended basics with a lot of possible solutions xD
Kind of hard to give a hint on... Wikipedia holds A LOT of answers
... Im not gonna post the exact article which helped me, because it tells you pretty much what to do... But look around - something in there might come in handy!
You guys playing around with functions as passthru, etc. are pretty close... You might want to take a VERY close look at whats special for the functions - which function is the best match for this task? (Small differences are important!)