Timesheet Job Code Pickup

Hi again,

Ok so same time sheet as I posted in a different post, but different questions.

Q1. Is there anyway that I can get Cells C17-23 to pick up the different Job codes from Cells N4-11?

For instance in cell C17 - it would pick up the Job No for cell N4 - and sum all the cells in column range D4:J11 which had the same job number.
Then if cell N8 was a different job, then cell C18 would show this new job number and sum all the cells in range D4:J11 for the new job etc.
given that a worker could work on 1 job on the Wednesday, Thursday and Monday, and a different job on the Friday, Saturday, Sunday and Tuesday.

Q2. I want to conditionally protect all the formula'd cells from being over written. However at times the cells may need to be over written due to a random set of conditions, is there a ways I can link a tickbox for each timesheet (given that there would be multiple timesheets on each spreadsheet tab), that will when ticked either allow or not allow someone to overwrite the formulas?

Hope the above is clear enough.

Ta in advance,

Matt