Change Geometrical Tolerance values c#

[grisel360]

How can I change Tolerance and Datum system of a Geometrical Tolerance in CATIA via c# or, if not, CATVBA .
So far I am only able to change the tolerance type, but have not find a method to change tolerance nor Datum system. Please help!

This is the code I got so far:

string feature_name = "GEN_TOL";
DrawingGDTs DrwTx = DwgDoc.Sheets.ActiveSheet.Views.Item("Background View").GDTs;
DrawingGDT geometricalTolerance = (DrawingGDT)DrwTx.GetItem(feature_name);
geometricalTolerance.SetToleranceType(1, 1);