Ability to replace values in DirectQuery

A competitor--Dundas BI--gives the user the ability to transform data without the need to import the data. This is possible because there is a database backend for Dundas BI. I would love to see this ability in Power BI Desktop--the ability to make transforms using DirectQuery that doesn't actually manipulate the data source. Specifically, I'd like to be able to use the "Replace Values" in DirectQuery to make some of my data more meaningful.