Oracle Projects Expenditure Web ADI - Is it possible to restrict expenditure type

Our business users have a requirement to restrict the expenditure type available on web adi based on the project type of the project already entered on web adi spreadsheet.

I wondered if the web adi uses a view, function, procedure etc to supply the list of expenditure types - and if so - if it is possible to modify this object?

The business has 3 requirements actually - the above being one:

1. Restrict list of values available to the expenditure types based on the project type for the project entered

2. validate the expenditure type based off the above requirement - sad face etc when it fails this validation