Hidden columns not to be unhidden by user

In a protected worksheet, where formatting columns is allowed (for user to be able to freely change column width), how can we ensure that hidden columns are kept hidden, ie user not to be allowed to unhide the hidden columns ?
Any help will be appreciated.

If you can format the columns then you can unhide columns. Can you not put the hidden columns on another worksheet which doesn't allow column formatting?

Originally Posted by royUK

Try protecting the workbook

Thank you Roy. I tried protecting the workbook but it did not help.

Originally Posted by brokenbiscuits

If you can format the columns then you can unhide columns. Can you not put the hidden columns on another worksheet which doesn't allow column formatting?

brokenbuscuits, thank you for your suggestion, but it is not practicable. Can you think of something else to try ?

How about locking the columns before hiding/protecting the workbook

Thanks MeatPuppet. Cells are already locked before hiding the column,but the problem still exists.