I can't reproduce your problem here. Creating a table with CCs and running
Code:
Sub ScratchMacro()
'A basic Word macro coded by Greg Maxey
On Error Resume Next
ActiveDocument.Unprotect
MsgBox "Test"
ActiveDocument.Protect wdAllowOnlyFormFields, True
End Sub
Runs without issue and I can type in all CCs.
Maybe you could try using editable regions and:
Code:
Sub ScratchMacro()
'A basic Word macro coded by Greg Maxey
On Error Resume Next
ActiveDocument.Unprotect
MsgBox "Test"
ActiveDocument.Protect wdAllowOnlyReading
End Sub