I'm going to have to go with the 'it's impossible without prior tampering' crowd. Someone's computer in front of them is (very) different to a deck of cards in your hand. Maybe while you force a card on them you get someone to hack into their computer over the wi-fi, or download a program off a USB stick, but otherwise, I doubt I'm going to believe this until you do it to my own laptop.
IF, however.... you CAN somehow manage this magic trick, then well done. Very well done. It is mighty impressive.