Sort a datagridTextColumn with an associated multivalueBinding

Hello there Fellows,

 I have a wpf DataGrid representing a ListCollectionView of "Person". In some column named "Total Income" there is a MultiBinding value converter that uses two properties of "Person" to calculate a int value. That works nicely.

 Now i want to get a list of all values in that Collum (the ones converted), so i can make some calculations.

 The reason is that i don't want to make those conversions again. 

  I want something like DataGrid.Collumns[X].getDisplayedValues();

Any tips?

Thanks!

-- Jorge_M_P