Percentage calculation Based on dates and remaining task 2013

Good day,
I am looking for help for the following formula:

C2 = Numbers of task
D2 = Start Date
E2 = End Date
F2 = Completed Task
G2 = Remaining Task

H2 = Total (Percentage)

I need to make H2 = Base on my start date and end date, the remaining task from my main task. Wow I'm reading this and makes no sense...

So I have lets says 10 task to do between the start date and end date. Each day I will complete a task. I have, in my column F2, a completed task. So each time I complete a task my remaining task changes. I would need to know what is the percentage of the remaining task based on the start date and end date.

Does this make any sense?

My Formula will be in H2

Does this make any sense?

Frankly, no! Please attach a workbook showing what you are expecting to see, preferably annotated.