Open .pln as only a Read-Only-File (intentionally)

[DOWA]

Hi, 
is there a way to open a single, (no teamwork!) .pln file as a read-only file,
when no one is using the file at the moment?
(I know that when the file is already open, Archicad asks if it should open read-only.)

Just like in Excel, one can select a file open it as read-only make calculations, but can't save. (only as Save As)
I find this method quite safe.

Thank you!

[Lingwisyer]

Even opening a file in DEMO mode will create a lck file putting it into an open state...