The function returns the name of given column of specified structure (or structure definition) as a text. Column is given by its serial number. Expression of Hbj type returns an object attribute \HBJ.
%GetColName(SV.Structure\HBJ, 1) ; returns the value of "Text"
%GetColName(SV.Structure\HBJ, 2) ; returns the value of "Int"
%GetColName(SV.Structure\HBJ, 10) ; returns invalid value