microsoft office professional 2003

i have a project schedule consisting of serveral tasks with different
durations for each task. i need to format one cell to show a start and
finsish date for each task and a final cell showing the total duration for
all tasks.

task 1 task 2 task 3 total duraction

5/29-6/2 6/3-6/10 6/11-6/12 ?????


thanks