Lock a range of cells base on current date relative to cell reference

Hi,

I want to lock the cells in in column B and C dependent on the date in Column A -10, relative to today’s date. I want this to be automatic upon opening the sheet.
Column A has the date Range A5:A16 starting with 1/1/15.
Column B & C are manual entry (unlocked cells) Range B5:C16
As the months progress I want to lock the Cells in column B & C

Example 1: if Today() = 4/9/15 then Cells B5:C8 are locked, but Cells B9:C16 are still unlocked.

Example 2: If Today() = 4/21/15 then Cells B5:C9 are locked, but Cells B10:C16 are still unlocked

See attached sheet excerpt to demonstrate what I'm trying to do.

Thank you!

Hi
Thank you, your code is close to what I'm looking for: there is an error in the loop, in the code. It does not seem to stop.

Scenerio:
Cells B5:C16 are unlocked, all other cells are Locked, Sheet1 is protected.
Unprotect sheet 1
Start: IF(Today()>(A5-10),LockCell,Nothing)
Continue until: IF(Today()>(A16-10),LockCell,Nothing)
Protect Sheet 1.
See Attached sheet for example of the run through on Rows 19 – 31.

Works Great, thank you for all your help!