Excel or matlab data processing

I need help with creating either an excel or matlab tool to convert fuel injection measurements into a duration map which can be used in a car ECU.

I have attached the excel sheet.
Essentially the raw data is in the tob table.
The lower table is what I need to fill in.
There looks to be a cubic relationship between the IQ and duration at each given pressure.
I need to solve these cubic equsations for each value of IQ to get the duration value.

Please take a look at the sheet and see if you need anymore explanation.
Ideally I would like it in script form so that I could use it again for different raw data sets.
Matlab is also an option.

Many thanks

Will