m_App.ActiveWorkbook.Sheets[1].Select();
var myWith = m_App.Selection;
 
myWith.Columns("A:A").ColumnWidth = 19.14f;
myWith.Columns("B:B").ColumnWidth = 23.43f;
myWith.Columns("C:C").ColumnWidth = 21f;
myWith.Columns("D:D").ColumnWidth = 12f;
myWith.Columns("E:E").ColumnWidth = 27.43f;