Stop calculating by inputting an end date.

[Dwebby]

Can anyone help please .
I've set up a spreadsheet to track an account. I have a start date for the account, then the daily cost, total days the account has been open(using the today function)and total cost to date.


Now what I am needing is an end date column with a formula that will stop calculating the total cost the date the account is closed.
Excel isn't my strength and I've been scratching my head for a few days trying to figure it out. All help extremely appreciated.