Hi Beautiful people of the Excel World.

So, I am hoping this is possible - I need a formula or something that will give a cell protection or unprotection based on what is in another cell.
For example, I have products of which some can allow for custom sizes, and some that cannot, so if the user enters the product code for an item in Cell B13, cell S13 will return a lookup result that states if that item will allow for special sizes. Cell H13 needs to be the cell in which the user can add the custom size if the item allows for it, so needs to unprotect itself based on the result in cell S13.

Another point to note, is that the worksheet is locked so users cannot mess with it.

Hoping it's possible, and that someone can help...