Collabora Online Excel Tab

Do you know how to modify presentation columns excel read only?
On some screens this is not very readable.

Hi Jerome,
(Noticing this one now…)
Do you mean that the content of columns is protected? Activating protection is not yet possible in Collabora Online.
Or do you mean that some columns (row) are frozen, and remain visible if the users moves far down or right? This is possible since some time with Format > Freeze Rows and Columns. and others.