Return Next working Day

Hi there, I think this may be impossible but what I am hoping to do is in B3 Return the date that is 3 working days before the date in B2. Working days being Monday to Friday in this case. so if the date in B2 is the 16/04/2014 3 days before this is the 13/04/2014 which is a Saturday so i would want the formula to return the 12/04/2014 which is the Friday

Is this possible?