I know you cannot have subsheets in Excel as it is not a hierarchical system.
I wondered if there was anyway of generating a similar end result though.

I have a list of engineers and I record the mileage they travel each week. I
am going to have another worksheet that records the private mileage they have
travelled, how much they have paid for that fuel and what MPG they claimed it
at. It would make life much easier if on the first worksheet there was a +
button next to each name that displayed the engineers corresponding figures
when clicked. Possible?