Conditional Formatting.
The Fill feature can do that.
On request, cells are automatically filled with data, usually based on cells above, or to the left.
You need to use Conditional Formatting.
It will immediately redraw the chart based on the new value
Yes, unless the chart is generated by a VB macro.
You can export a spreadsheet to HTML to view on the Web, but you can not operate Excel from a web browser.
There is something called a workbook dump. It is excel-based, and can be used to export data from HySYS to excel.
It is not time based. Normally Excel is in what is known as Automatic Recalculation mode. When this is the case Excel recalculates any time any change is made to the spreadsheet, like typing in a new number or a piece of text. If it is in Manual Recalculation mode, then it only recalculates when the user presses the F9 key.
A chart in Excel is dynamic, meaning it will automatically change as the data changes. A paper based chart won't do that. Excel charts can have all sorts of features and can be customised to the way the user wants. Those are some of the advantages. A paper based chart can sometimes be more accurate than an Excel one in the way it is drawn, like X Y diagrams. It is much easier to add notes to the chart when it is printed. A user can handwrite on it to make important notes about it.
You do Conditional Formatting based on a cell value or based on a formula.
Filter.
An IF formula.