You can override 'createColumn' method and adjust the column information. You just need to cast ColumnDef arg3 argument to DefaultColumnDef so you can update some properties. Then you have to send this updated DefaultColumnDef object into former createColumn method ...
@Override
public IControl createColumn(FacesContext arg0, UIDynamicViewPanel arg1,int arg2, ColumnDef arg3) {
DefaultColumnDef dc=(DefaultColumnDef) arg3;
dc.title=arg3.getTitle()+"some your text";
// send DefaultColumn object into former createColumn method ...
IControl col = super.createColumn(arg0, arg1, arg2, dc);
return col;
}