If you want to prevent the user from sorting on a specific column, set the ColUserSortIndicator property as follows.
Specify the column number using the Col parameter.
Set the property to 3 (Disabled).
Set the UserColAction property to one of the following values to specify what action to perform when the user clicks any column header:
If you want the column to be sorted when the user clicks a column header and to display the sort indicator, set the UserColAction property to 1 (Sort).
If you want the column to be sorted when the user clicks a column header and to not display the sort indicator, set the UserColAction property to 2 (SortNoIndicator).
If your sheet displays multiple headers and you want the sort indicator to display in a row other than the bottom-most header row, specify which column header row will display the indicator by setting the ColHeadersUserSortIndex property.