We should be able to add a field temporarily in reports which will be a transformed version of exist

User should be able to add a field in the reports which will be a transformed version of any existing field and this field can be a temporary one which has its life only for that report. For example, consider below use cases,
1) Appending 2 fields and showing it as single field (like appending "First Name" and "Last name" and displaying it as "Name")
2) Transforming a numeric field into percentage, showing difference between 2 numeric fields and so on(Currently we are having calculated fields to cover this use case)
3) Since we are introducing currency data type, we should also be able to support currency conversion. Since it is a standard formula and the only change will be the conversion rate which we can update, this could be doable.
4) We should be able to do some logic like if case A, then implement choice 2