Avoid Copying Cell Protection Without Macro

[lgalster]

I need help finding a solution to the following problem!:

I have a range of unlocked cells pinned on the corners by locked cells. Users are allowed to only select unlocked cells. Therefore the user cannot select the first or last row or column (thus nor can they delete, which is the intent), but the user can insert and delete columns at will within the range.

The crux of the problem is that because formats are copied from above or from the left, inserting a row below the first row in the user range or inserting a column before the first column in the user range pins the newly inserted row or column on the outside because it copies the locked cell format from the row above or from the column to the left. How can I avoid that protection from being copied without using a macro?

I could use a macro if it wouldn't erase the undo cache, but my understanding is that it would erase it.

Here's an image that may clarify (or confuse if it doesn't appear properly):

--------------------------------
|Lock| | | | |Lock|
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|Lock|User|User|User|User|Lock|
--------------------------------
| |User|User|User|User| |
--------------------------------
| |User|User|User|User| |
--------------------------------
|Lock|User|User|User|User|Lock|
--------------------------------
|Lock| | | | |Lock|
--------------------------------

I need your help! Thank you!!

-Lance