Selected Answer
You need a macro for this.
Hit Alt+F11 and insert this macro into the Sheet module where the selections are going to be made. This macro below assumes that it is on Sheet1.
Here is a macro that should work for you:
Private Sub Worksheet_Change(ByVal Target As Range)
If Not Target.Address = "$A$2" Then Exit Sub
If Target.Value = "c" Then
'unprotect the sheet
Sheets("Sheet1").Unprotect
'protect the cells so they can't be changed
Range("B2").Locked = True
Range("C2").Locked = True
Range("D2").Locked = True
'protect the worksheet so the cells can't be changed
Sheets("Sheet1").Protect
Else
'unprotect the sheet
Sheets("Sheet1").Unprotect
'protect the cells so they can't be changed
Range("B2").Locked = False
Range("C2").Locked = False
Range("D2").Locked = False
'protect the worksheet so the cells can't be changed
Sheets("Sheet1").Protect
End If
End Sub
$A$2 is the address of the cell where the selection will be made. Dollar signs must go infront of the letter and number of the cell address. You must also unlock this cell to begin with by hand. Right-click > Format Cells > Protection tab > uncheck Locked and hit OK.
Sheet1 is the name of the sheet where the selection will be made.
B2 C2 and D2 are the cells where the other options should be located.
c is the value that cell A2 should have to cause the other options to not be able to be selected.
Notes:
There is currently no password required to lock or unlock the sheet.
Also, you must unlock any other cells on the worksheet that you want to be able to be changed or accessed once the worksheet has been protected. Right-click > Format Cells > Protection tab > uncheck Locked and hit OK.
