This is OneStream, of course it's possible 😁 and as with everything in OneStream, there is more than one way to go about it...
One approach is to enable an Attribute Value dimension (in the Integration tab of your Cube), add it to the DataSource, and map it to the column. This will bring the numbers to Stage tables, and from there you can do anything you want with them from a Business Rule.
Another approach is to use a Derivative Rule that executes on all records, taking the Volume and generating new records where its number is mapped to Amount (against some other intersection, of course).
Another approach is to have two datasources: one where Amount is mapped to Amount and one where it's mapped to Volume - again, they will obviously target different intersections.
(Note: When I say "different intersections", I mean they will be stored against different metadata members. You would probably have two different Account members, one of them NonFinancial.)