All cells on the WS are Locked=False, except for B4:E14 which are Locked = True
More that that, you'll have to figure out the other specifics
Option Explicit
Private Sub CommandButton1_Click()
Dim r As Range, r1 As Range
On Error Resume Next
Set r = Range("A4:A14").SpecialCells(xlCellTypeConstants, xlNumbers)
On Error GoTo 0
If r Is Nothing Then Exit Sub
Me.Unprotect "abc"
For Each r1 In r.Cells
If Len(r1.Offset(0, 1).Value) = 0 Then
r1.Offset(0, 1).Value = Format(Now, "HH:mm:ss")
r1.Offset(0, 1).Locked = True
r1.Resize(1, 5).Interior.Color = 13434879
End If
Next
Me.Protect Password:="abc", UserInterfaceOnly:=True
End Sub