I've been trying to do a similar thing today (high five!).
This script:
http://www.armaholic.com/page.php?id=25458

Its not exactly what you want, as it requires anyone you want to para jump to be in a vehicle. However, with some minor tweaks you can just pass the player to the script and it will sort out the rest. Bonus being that you can give your ai/ you backpacks.