Retrieve total hours for a project

[shod90]

Dear all ,
I have a form which i should fill all the data related to a specific project (StartDate,EndDate,Duration,RemainingHours , Bla bla bla )
now the problem is in the remaining hours , the equation of remaining hours should be Assigned Hours ( Given already ) - Calculated hours ( here is the problem )
How can i calculate total hours for a project for all users till current date ??

the question in another way would be : How can i retrieve totals from report and insert it in a calculated field in a query or form ?

[ranman256]

You're NOT supposed to update calculated fields to a table.
you sum the hours in a query.