C# datagridview row enforcing casing

Based on somebody's answer to a previous question, I enforce character casing in datagridview cells as seen in the attached code.

Now I need to selectively enforce casing.  That is, for colDesc1 I don't want to enforce casing whereas for colItemNo I do want to enforce casing.

I can't find a way to do this.  I tried e.Control.Name, but it is an empty string.  I noticed e.Control.Tag, but cannot assign a tag in the datagridview interface.  I tried e.Control.Location, but that didn't work.

Any suggestions?

private void dgvMain_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
        {
            if (e.Control is TextBox)
                ((TextBox)e.Control).CharacterCasing = CharacterCasing.Upper;
        }